Intraoperative navigation for shoulder arthroplasty - where are we going?

Computer-assisted navigation systems for shoulder replacement surgery are - like robotics (see What should be the role of robotics in shoulder arthroplasty?) - commercially advocated to aid surgeons in positioning components to match a preoperative plan based on a static preoperative CT scan.

Opinions vary among expert surgeons regarding which component positions (e.g. glenosphere position, lateralization, inclination; humeral distalization and lateralization) optimize patient reported comfort and function on one hand and minimize the risk of important complications (such as instability/dislocation and acromial/spine stress fractures) on the other. Furthermore the preoperative plan is formed in the absence of important intraoperative findings (such as soft tissue balance and bone characteristics) that are observed after the shoulder is surgically exposed and that often require the surgeon to modify the preoperative plan.

Let's consider a recent systematic review, The Role of Intraoperative Navigation in Reverse Total Shoulder Arthroplasty and its Impact on Clinical Outcomes: which assessed five studies with nearly 2,000 patients having reverses total shoulder carried out using ExactechGPS Navigation.

Three studies directly compared navigated versus conventional non-navigated reverse shoulder replacement. All three showed the same result: no clinically significant differences in functional outcomes.

Short-term clinical and radiologic outcomes of reverse total shoulder arthroplasty with navigation system in the Asian population: a retrospective comparative study found "the use of a navigation system in rTSA showed no significant difference in clinical outcomes and complications compared to conventional implantation."

Early clinical outcomes following navigation-assisted baseplate fixation in reverse total shoulder arthroplasty: a matched cohort study found: "navigated and non-navigated RSAs yielded similar rates of improvement in range of motion and functional outcome scores"

 Intraoperative navigation system use increases accuracy of glenoid component inclination but not functional outcomes in reverse total shoulder arthroplasty: a prospective comparative study. found "There were no statistically significant differences in ROM, PROMs, and satisfaction between patients receiving computer-navigated and standard RSA at a short-term follow-up. "

The review paper (The Role of Intraoperative Navigation in Reverse Total Shoulder Arthroplasty and its Impact on Clinical Outcomes) does not report comparative cost, surgical time, revision rates, or complication rates for patients receiving navigated and non-navigated reverse total shoulders. Furthermore, the article does not address the learning curve for this technology and whether this is a reasonable undertaking for the many surgeons who perform  relatively few reverse total shoulders per year.

Notably absent from all published studies is a comparative cost analysis. The proprietary nature of navigation system pricing—where capital equipment, disposables, software, and per-case fees create opaque total costs—prevents the field from conducting basic cost-effectiveness evaluation. 

There is yet another issue: that of complications related to the navigation system itself, such as problems with fixation of the device to the coracoid. Coracoid fracture represents an uncommonly reported but specific complication of navigation-assisted shoulder arthroplasty, with an overall reported incidence of approximately 0.05% in experienced hands but significantly higher rates (up to 30%) during the learning curve. 

High intraoperative accuracy and low complication rate of computer-assisted navigation of the glenoid in total shoulder arthroplasty analyzed 16,723 navigated shoulder arthroplasty cases reported 9 coracoid fractures.

GPS NAVIGATION SYSTEM ALLOWS THE SURGEON TO PREPARE THE IMPLANT SITE AS PLANNED ON PREOPERATIVE SOFTWARE IN REVERSE SHOULDER ARTHROPLASTY: 3 coracoid fractures in the first 10 cases

THE USE OF NAVIGATION IN REVERSE SHOULDER ARTHROPLASTY: PRELIMINARY REPORT OF 11 CASES: 1 fracture in the first case.

Safety and Efficacy of Intraoperative Computer-Navigated Versus Non-Navigated Shoulder Arthroplasty at a Tertiary Referral: 2 cases (5.5%) of coracoid fracture.

If you are curious, here's some detail about the ExactechGP Navigation system.  You might like by looking at this video

The Basic Technology -  

The Components:

1. Preoperative Planning

    * Patient gets a CT scan of their shoulder

    * Surgeon uploads CT to Equinoxe Planning App software

    * Surgeon creates a 3D virtual plan: glenoid component position, version, inclination, depth, screw trajectories

    * Within days, the plan is uploaded to GPS workstation

2. Intraoperative Hardware

GPS Workstation:

    * Compact mobile unit within sterile field

    * Has an infrared camera that tracks the LED markers

    * Screen displays real-time surgical guidance

Three Active Trackers (reusable, battery-powered with IR LEDs):

    * Probe Tracker: Hand-held pointer for registration

    * Glenoid Tracker: Attached to coracoid process (bone stabilizer)

    * Tool Tracker: Attached to surgical instruments (reamers, drill guides)

3. The Workflow

Step 1: Registration (Mapping CT to Patient)

    * Surgeon attaches Glenoid Tracker to coracoid process with a pin

    * Using the Probe Tracker, surgeon touches specific anatomic landmarks on the scapula

    * System matches these physical points to the CT scan

    * Creates a "coordinate system" linking the patient's real anatomy to the virtual plan

Step 2: Real-Time Guidance

    * Surgeon attaches Tool Tracker to reamer/drill/guide instruments

    * Camera tracks all three trackers simultaneously via their IR LEDs

    * Screen shows:

        o Current instrument position vs. planned position

        o Version and inclination in real-time

        o Reaming depth

        o Screw trajectories and lengths

Step 3: Verification

    * After component placement, system verifies final position

    * Compares achieved vs. planned placement

Conclusion:

The question each surgeon must ask is whether intraoperative navigation addresses problems experienced by patients in their own practice having reverse total shoulder arthroplasty.

The question the field of shoulder surgery must ask is which specific patient problems (instability? fracture? stiffness? pain?) occur due to positioning errors that: (a) surgeons using standard techniques cannot adequately control, and (b) navigation systems would prevent. 

Finding the way

Snow Geese 

Skagit, Washington

202

Follow on twitter/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link)
The total shoulder arthroplasty (see this link)
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)

Shoulder rehabilitation exercises (see this link). 

Rethinking rotator cuff tear management - how do we want to spend the money?

The management of patients with rotator cuff tears presents a significant clinical and economic challenge. With annual costs of rotator cuff surgery exceeding $3 billion in the United States alone, and increasing evidence that structural repair does not always correlate with functional outcomes, a critical reassessment of the cost-effectiveness of different management options seems warranted. 

Let's start with a case example

A 70 year old active skier, cyclist, climber and practicing orthopaedic surgeon presented with the progressive onset of pain in the right shoulder. Physical examination revealed weakness of resisted elevation, but a good range of active motion. Plain radiographs showed no evidence of arthritis. The MRI findings are shown below.  

Surgical repair was offered but declined in favor of a home exercise program. A decade later the shoulder has a full painless range of range of motion and strength sufficient for sports and surgical practice. 

An Overview

Prevalence, Natural History, and Nonoperative Treatment of Rotator Cuff Disease

Rotator cuff disease is extremely common, affecting up to 25% of the population over age 40. Tear prevalence, size, likelihood of progression, and retear rates after surgical repair are all related to increasing age. Fewer than 5% of people with rotator cuff tears come to surgery, the great majority of rotator cuff tears are either asymptomatic or mildly symptomatic. 

However, Over a half million cuff surgeries are performed each year and this number is increasing

Non-operative treatment represents the most cost-effective strategy for many patients with symptomatic rotator cuff tears.

Jed Kuhn and the MOON (Multicenter Orthopaedic Outcomes Network) Shoulder Group that he leads published Effectiveness of physical therapy in treating atraumatic full-thickness rotator cuff tears: a multicenter prospective cohort study, a multicenter prospective cohort study of 452 patients with atraumatic full-thickness rotator cuff tears treated with a standardized physical therapy protocol. The study found that 75% of patients achieved successful outcomes with physical therapy alone at 2-year follow-up, with "failure" defined as patients electing to undergo surgery. 

The Predictors of Surgery for Symptomatic, Atraumatic Full-Thickness Rotator Cuff Tears Change Over Time: Ten-Year Outcomes of the MOON Shoulder Prospective Cohort, a follow-up study tracked the original cohort for 10 years and found that physical therapy remained successful in over 70% of patients, with only 27% ultimately requiring surgery. Importantly, patient-reported outcomes improved with physical therapy and did not decline over the 10-year period. This study won the 2024 Kappa Delta Ann Doner Vaughan Award and demonstrated the long-term durability of non-operative treatment.

EXERCISE THERAPY IN THE NON-OPERATIVE TREATMENT OF FULL-THICKNESS ROTATOR CUFF TEARS: A SYSTEMATIC REVIEW Of the non-operatively treated cohorts 78% improved in pain, 81% improved in range of motion, 85% improved in strength, 84% improved in functional outcomes. Dissatisfied outcomes occurred in 15% of patients, who then transitioned to surgery.

The cost differential is substantial. Home exercises are inexpensive and often effective. While comprehensive physical therapy may cost $1,500-3,000 over several months, surgical repair typically ranges from $15,000-25,000, creating a 10-fold cost difference for initial treatment. Given that many patients achieve acceptable outcomes with therapy alone, this represents a significant opportunity for cost savings without compromising patient outcomes.

Patient selection for non-operative management should prioritize older individuals (typically >65 years), those with maintained active forward elevation without pseudoparalysis, reasonable functional demands, and chronic rather than acute tears. 

Symptoms of cuff tears do not correlate strongly with the magnitude of the defect.

Symptoms of pain do not correlate with rotator cuff tear severity: a cross-sectional study of 393 patients with a symptomatic atraumatic full-thickness rotator cuff tear, A cross-sectional study of 393 patients with symptomatic atraumatic full-thickness rotator cuff tears demonstrated that pain severity does not correlate with tear size or other anatomic features. This finding challenged the assumption that larger tears necessarily cause more symptoms and require more aggressive treatment.

Patient self-assessed shoulder comfort and function and active motion are not closely related to surgically documented rotator cuff tear integrity found that cuff integrity was not strongly associated with the shoulder's comfort or function. 

Repair attempts often lead to failure of anatomic healing of the tendon to bone; clinical outcomes are largely independent of repair integrity.

Arthroscopic repair of full-thickness tears of the supraspinatus: does the tendon really heal? Only 43% of patients over the age of sixty-five years had completely healed tendons.

Failure with continuity in rotator cuff repair "healing" found that all rotator cuff repairs retracted substantially away from their position of initial fixation during the first year after surgery (mean 16.1 ± 5.3 mm; range, 5.7-23.2 mm), yet only 30% of patients showed a defect on MRI. This study is important because it indicates that an "intact" tendon repair on MRI may not indicate healing of the tendon to the insertion site. This finding may be especially relevant to the assessment of repair integrity after the use of patches and grafts.

The outcome and repair integrity of completely arthroscopically repaired large and massive rotator cuff tears reported arthroscopic repair of large and massive rotator cuff tears led to a high percentage of recurrent defects. The minimum twelve-month evaluation showed excellent pain relief and improvement in the ability to perform activities of daily living despite the high rate of recurrent defects.

Rotator cuff repair: published evidence on factors associated with repair integrity and clinical outcome found that the mean re-tear rate was 26.6% at a mean of 23.7 months after surgery.  Patient-reported outcomes were generally improved whether or not the repair restored the integrity of the rotator cuff.  In spite of a dramatic increase in the number of publications per year and the advent of biologic augmentation there was little evidence that the clinical results of rotator cuff repair were improving with time. 

Structural Integrity After Rotator Cuff Repair Does Not Correlate with Patient Function and Pain The differences in validated functional outcome scores and pain were not clinically significant for intact and failed repairs.

Non-repair surgery - the underutilized "smooth and move" procedure / debridement (see this link)

Smoothing the humeroscapular motion interface without acromioplasty is a quick, safe procedure for painful cuff tears in shoulders with preserved active elevation. It allows the patient immediate return to use of the shoulder without postoperative "down time". It does not involve use of a more costly "subacromial balloon" or a "biological tuberoplasty". The cost-effectiveness advantages of debridement are substantial. Operative time is typically 30-45 minutes compared to 2-3 hours for complex repairs, resulting in lower facility and anesthesia costs. Recovery is faster, allowing quicker return to activities and reduced rehabilitation expenses. Complication rates are lower due to the less invasive nature of the procedure.

Treatment of irreparable cuff tears with smoothing of the humeroscapular motion interface without acromioplasty.  In 77 shoulders with previously unrepaired irreparable tears, simple shoulder test (SST) scores improved from an average of 4.6 to 8.5. Fifty-four patients (70%) improved by at least the minimally clinically important difference (MCID) of 2 SST points. For 74 shoulders with irreparable failed prior repairs, SST scores improved from 4.0 to 7.5. Fifty-four patients (73%) improved by the MCID. This conservative procedure offers an alternative to more complex procedures in the management of irreparable rotator cuff tears.

Significant improvement in patient self-assessed comfort and function at six weeks after the smooth and move procedure for shoulders with irreparable rotator cuff tears and retained active elevation In 40 patients with preoperative and 6-week postoperative measurements, the Simple Shoulder Test scores improved from an average of 3.4 ± 2.8 preoperatively to 5.7 ± 3.5 at 6 weeks (p < 0.001), an improvement that exceeded the published values for the minimal clinically important difference (MCID). The clinical outcomes were not worse for the 18 shoulders with irreparable tears of both the supraspinatus and infraspinatus. In addition to its previously documented long-term effectiveness for shoulders with irreparable rotator cuff tears and retained active elevation, this study demonstrates that the smooth and move procedure provides clinically significant improvement as early as 6 weeks after surgery.

Comparing outcomes between debridement and attempted repair of large/massive tears reveals only modest functional differences, yet the repair costs more and carries higher complication risks.

Massive rotator cuff tears: functional outcome after debridement or arthroscopic partial repair Both treatment groups had similar pain relief and satisfaction, reflected in equal values of disabilities of the arm, shoulder and hand (DASH) score. Ultrasonography revealed structural failure of the partial rotator cuff repair in 52% at final follow-up.

Partial rotator cuff repair versus debridement for irreparable rotator cuff tears: A systematic review 709 shoulders from 706 patients were reviewed, with 380 patients receiving a partial repair and 329 shoulders receiving debridement.  Pre- and post-operative mean VAS scores were the same for both treatments. Patient satisfaction with partial repair was reported as 75 %; for patients treated with debridement, post-operative satisfaction was 80.7 %.This systematic review study demonstrates that both partial repair and debridement alone can result in acceptable clinical outcomes with no significant differences noted for patients with irreparable rotator cuff tears in short to mid-term follow up.

Standard Rotator Cuff Repair

Standard surgical repair remains the gold standard of treatment for cuff tears when the quantity and quality of the tendon is adequate. The outcomes of cuff repair surgery are strongly influenced by the patient's nutrition. See: The "Secret Sauce" for Optimizing Rotator Cuff Outcomes: Biologics or nutrition?

Biologics, patches, PRP, and augmentation 

While these interventions are associated with reduced retear rates there is currently insufficient evidence that their significantly increased costs result in clinically meaningful improvement in clinical outcomes for patients. Structural healing on imaging does not reliably translate to better clinical outcomes for patients. This disconnect persists despite 25+ years of rotator cuff biological augmentation research.

Platelet-Rich Plasma (PRP)

Use of platelet-rich plasma for the improvement of pain and function in rotator cuff tears: a systematic review and meta-analysis with bias assessment Improvements in PRP-treated patients were noted for multiple functional outcomes, but none reached their respective minimal clinically important differences

Clinical and structural outcomes after arthroscopic repair of full-thickness rotator cuff tears with and without platelet-rich product supplementation: a meta-analysis and meta-regression. A meta-analysis of Level I and II studies found no statistically significant differences in overall outcome scores or retear rates between PRP-treated and control groups.

Evaluating the longitudinal efficacy of platelet-rich plasma in rotator cuff surgery: a systematic review and meta-analysis While PRP reduced pain (VAS) in the early postoperative period, the improvement was not clinically significant.

Platelet-rich plasma for arthroscopic repair of large to massive rotator cuff tears: a randomized, single-blind, parallel-group trial found that despite better structural healing in the PRP group, there was no clinically significant difference in outcomes between groups.

Cost: Approximate per-procedure expense of PRP:  preparation kits: $600 per case; 15 min additional OR time for preparation ($600), processing equipment ($3,000-15,000). The Cost-Effectiveness of Using Platelet-Rich Plasma During Rotator Cuff Repair: A Markov Model Analysis This cost-utility analysis shows that, currently, the use of PRP to augment rotator cuff repair is not cost-effective.

Scaffold and Patch Augmentation

The clinical adoption of these technologies raises questions about their actual effectiveness in improving patient outcomes, their cost-effectiveness in real-world practice, and their safety profile. 

A prospective, randomized evaluation of acellular human dermal matrix augmentation for arthroscopic rotator cuff repair found the change in ASES, Constant, and UCLA scores were not clinically signficantly better (did not exceed MCID) for the matrix augmentation group than for the controls.

A pilot randomised controlled trial assessing standard versus dermal patch-augmented rotator cuff repair found no adverse effects and suggest future trials need a minimum of 150 patient Among 40 patients randomized to augmented repair versus standard repair there was no difference between groups with respect to clinical outcomes.

Clinical and anatomical outcomes of arthroscopic repair of large rotator cuff tears with allograft patch augmentation: a prospective, single-blinded, randomized controlled trial with a long-term follow-up This prospective, single-blinded RCT compared arthroscopic repair of large rotator cuff tears with vs. without allograft dermal patch augmentation at mean 7.3-year follow-up. Clinical outcomes (Patch vs. Control at final follow-up): VAS pain: 1.3 vs. 1.5 (difference 0.2 - clinically insignificant) ASES: 87.9 vs. 86.1 (difference 1.8 points - well below MCID of 6.4) Constant: 82.6 vs. 79.5 (difference 3.1 points - well below MCID of 10.4)UCLA: 32.0 vs. 31.0 (difference 1.0 point - below MCID) SST: 10.2 vs. 9.6 (difference 0.6 - below MCID of ~2 points). None of these differences were clinically significant.

Outcome of Large to Massive Rotator Cuff Tears Repaired With and Without Extracellular Matrix Augmentation: A Prospective Comparative Study Uniquely, this study showed a clinically significant difference in ASES score with matrix augmentation.

Cost: Resorbable Bioinductive Collagen Implant Is Cost Effective in the Treatment of Rotator Cuff Tears Average cost of treatment $32,213 without Regeneten, $54,459 with Regeneten (additional cost 69%). The authors did not assess patient reported outcomes or revision rates for patients without or with the patch. While using "healing" as the study endpoint, the authors point out that there is lack of agreement on what constitutes healing or re-tearing after a cuff repair based on magnetic resonance imaging, ultrasound, or arthrogram. Evidence was not presented that "healing" by imaging correlated with better clinical outcomes .

Economic Evaluation of a Bioinductive Implant for the Repair of Rotator Cuff Tears Compared with Standard Surgery in Italy. Average cost of treatment €4650 without Regeneten, €7828 with Regeneten (additional cost 68%). Study limitations the same as those for the report above.

Complications: 

Increased stiffness and reoperation rate in partial rotator cuff repairs treated with a bovine patch: a propensity-matched trial found that postoperative stiffness was observed in the first 12 weeks in 8 of 32 patients in the Regeneten patch group compared with 1 of 32 patients in the control group. Six patients in the patch group underwent reoperations compared with no patients in the control group. All 6 reoperations in the patch group were performed to address stiffness. The authors concluded that patients in the patch group had a significantly higher rate of postoperative stiffness. In the majority of patients in whom shoulder stiffness developed, reoperation was required. 

Subacromial-Subdeltoid Bursitis With Rice Bodies After Rotator Cuff Repair With a Collagen Scaffold Implant: A Case Report. reported a case of subacromial-subdeltoid bursitis with rice bodies after rotator cuff repair with a Smith + Nephew REGENETEN bovine-derived bioinductive collagen scaffold implant. After debridement, the patient recovered well and made a full return to work and recreational activities.

Revision arthroscopic surgery after rotator cuff repair with a collagen graft: histologic evaluation of biopsy specimens from two patients. Patients undergoing collagen scaffold augmentation should be warned of the possibility of reactive bursitis. Cases of reactive bursitis may need to be managed with surgical débridement to treat symptoms and structural failure and to rule out infection. 

Restore orthobiologic implant: not recommended for augmentation of rotator cuff repairs  Years after surgical repair of large rotator cuff defects supplemented with a xenograft, patients had persisting deficits and no recognizable benefit as compared with the results in a control group. In view of these findings, together with the unsatisfactorily high proportion of patients with a severe inflammatory reaction to the xenograft, the authors do not recommend use of the Restore Orthobiologic Implant.

Subacromial-Subdeltoid Bursitis With Rice Bodies After Rotator Cuff Repair With a Collagen Scaffold Implant: A Case Report This case demonstrates persistent pain, swelling and decreased range of motion for several months after rotator cuff repair with the use of a collagen implant

Severe subacromial-subdeltoid inflammation with rice bodies associated with implantation of a bio-inductive collagen scaffold afterrotator cuff repair  The potential for an acute, significant painful phase in a patient’s recovery should be part of the informed-consent process when using the Regeneten implant.

These findings suggest that reactive bursitis may be an under-recognized complication of biological patch augmentation, potentially contributing to the increased stiffness rates observed in larger series. What makes these complication rates concerning is their infrequency in control groups. In the propensity-matched study, zero patients in the standard repair group required reoperation, while 19% of patch-augmented patients did experience this novel category of complications associated with the augmentation material itself.

Conclusions:

(1) Age-relared rotator cuff failure is common and very often minimally symptomatic.

(2) Physical therapy can be cost-effective in improving comfort and function for the majority of patients with these tears.

(3) Non-repair surgery (smooth and move/debridement) can be cost-effective for patients with retained active elevation

(4) Surgical repair can be cost-effective when there is adequate quantity and quality of cuff tendon.

(5) PRP and "biologic" patches have not been shown to be cost-effective in improving patient reported outcomes. Sponsored 'cost-effectiveness' studies measuring surrogate endpoints (e.g. healing by imaging) rather than patient-centered outcomes may be misleading by not considering patient outcomes and complications.

Looking the problem in the eye.

Red-faced Warbler

Tucson

Spring 2020

Follow on twitter/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link)
The total shoulder arthroplasty (see this link)
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)

Shoulder rehabilitation exercises (see this link). 

Super bowl - Superb owl

.

FYI, another name for an Osprey is a Sea Hawk

Be there!

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The Bad B2 Pandemic Continues - by now, you can guess the treatment we selected.

Here's a case from last week: 40 year old very active man with these x-rays 

From the white board in the OR, ROM under general anesthesia

Thus we have the familiar B2 paradox: a posteriorly decentered, unstable shoulder that is also stiff (FE -forward elevagion; ER - external rotation at the side; ERA - external rotation in abduction; IRA - internal rotation in abduction; CBA - cross body adduction (distance from antecubital fossa of surgical arm to contralateral acromion in cm)).

From the responses to the Jan 29 post, many surgeons would consider a reverse total shoulder, or an anatomic total shoulder with a posterior augment.

Our preop preview suggested a 50 20 humeral head. A preoperative CT was not obtained.

As usual the procedure was performed under a general anesthesia without nerve block. The shoulder was approached through a subscapularis peel, preserving the long head tendon of the biceps.

At surgery, the glenoid was biconcave in the posterior inferior direction (ellipse) rather than directly posterior with respect to superior / inferior axis (yellow line). This pathoanatomy would have been difficult to fit using an augmented glenoid component without excessive bone removal.

The glenoid was conservatively reamed to a monoconcavity without attempting to change glenoid version.

A short humeral stem was inserted.

As pointed out in prior posts, the key is not a preoperative plan or attempting to match a preoperative plan with expensive technology (e.g. robotics, patient specific instruments, virtual reality, or augmented reality). These approaches do not recognize the importance of soft tissue balancing. 

Instead, we use intraoperative decision-making after osteophyte resection and appropriate tissue releases that recognize the soft tissues' and the implants' combined contributions to the shoulder's mobility and stability.

Trialing with the standard 50 20 head revealed excessive soft tissue tightness on the 150, 40, 50, 60 tests. Trialing with the strandard 50 18 head revealed excessive posterior translation.

Trialing with the anterioly eccentric 50 18 head revealed excellent balance of stability and mobility (160 FF, ER 20, IRA 60, 50% posterior translation). 

His postoperartive range of flexion is shown here

His recovery room films are shown here

For comparison, here's his preoperative axillary 'truth' view (note the standardization of the projection and arm position)

We will start assisted flexion at 2 weeks post op.

See also the case at the top of this page under the W

It's all about balance

Black-necked Stilt

Malheur National Wildlife Refuge

Spring 2025

Follow on twitter/X: https://x.com/RickMatsen
Follow on facebook: https://www.facebook.com/shoulder.arthritis
Follow on LinkedIn: https://www.linkedin.com/in/rick-matsen-88b1a8133/

Here are some videos that are of shoulder interest
Shoulder arthritis - what you need to know (see this link).
How to x-ray the shoulder (see this link).
The ream and run procedure (see this link)
The total shoulder arthroplasty (see this link)
The cuff tear arthropathy arthroplasty (see this link).
The reverse total shoulder arthroplasty (see this link).
The smooth and move procedure for irreparable rotator cuff tears (see this link)

Shoulder rehabilitation exercises (see this link). 

The Bad B2 in active patients - the ream and run using the anteriorly eccentric humeral head to recenter the joint.

The Bad B2 glenoid is frequently encountered in our arthroplasty practice. In a previous post I presented the two cases of quality of life limiting Bad B2 pathoanatomy below for thoughts on management. Options included reverse total shoulder, anatomic total shoulder without or with augmented glenoids or bone grafting, and various types of hemiarthroplasty. 

Each patient was treated with the classic ream and run using an anteriorly eccentric humeral head to re-center the posteriorly unstable articulation. No preoperative CT scan or 3D planning were used in either case. The procedures were performed under general anesthesia without a plexus block. The long head tendon of the biceps was preserved in both cases. The subscapularis was peeled and repaired with six fiberwire sutures and a mild rotator interval closure.

Coincidentally, both patients returned for their two-year followups on the same day. Both reported the ability to perform each of the 12 functions of the Simple Shoulder Test. Both had strong subscapularis function.

51 year old active man

64 year old active man

Cutting to the chase

Scissor-tailed Flycatcher

Austin, Texas

 2025

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