Problems, complications, reoperations, and revisions in reverse total shoulder arthroplasty: a systematic review

Reverse shoulder arthroplasty for proximal humeral fractures: update on indications, technique, and results

The introduction of the reverse shoulder arthroplasty has provided shoulder surgeons with more options for the treatment of complex proximal humeral fractures in the elderly. Early reported results suggest that the average functional outcome may be better than hemiarthroplasty in certain patients and specific clinical scenarios. In addition, these results seem to be reached more quickly with less dependence on rehabilitation. The reverse prosthesis may be particularly useful in patients aged older than 70 years, especially those with severely comminuted fractures in osteopenic bone. These factors likely have a negative impact on the results of hemiarthroplasty and internal fixation. Despite the potential benefits of reverse arthroplasty for fracture, there is a significant learning curve with the use of this prosthesis, and it has its own set of complications. The surgeon must show appropriate judgment when selecting a reverse arthroplasty in the setting of a proximal humeral fracture and, furthermore, be well acquainted with the surgical technique and prosthetic options at the time of surgery. Although the longevity of this prosthesis remains unknown, midterm outcomes are promising.

Clinical outcome of reverse total shoulder arthroplasty combined with latissimus dorsi transfer for the treatment of chronic combined pseudoparesis of elevation and external rotation of the shoulder

BACKGROUND

Reverse total shoulder arthroplasty (RTSA) allows correction of pseudoparesis of elevation caused by irreparable rotator cuff tear but does not address loss of active external rotation. Latissimus dorsi transfer (LDT) is an established procedure for correction of pseudoparesis of external rotation.

METHODS

Forty-one shoulders of 40 consecutive patients, who were a mean age of 70 years old (range 47-85 years), underwent RTSA combined with LDT for irreparable rotator cuff failure with severe shoulder dysfunction.

RESULTS

Nine orthopedic complications occurred in 7 of the 41 shoulders. Four shoulders were lost to follow-up, and 5 were excluded from the functional analysis. The mean follow-up of the eligible 32 shoulders with the prosthesis still in place was 53 months (range, 24-105 months). The age-related Constant score increased significantly from a preoperative mean of 45% (range, 16%-80%) to 89% (range, 25%-100%). The mean subjective shoulder value increased from 33% (range, 0%-70%) to 75% (range, 30%-100%). Active external rotation significantly improved from a mean of 4° (range, -30° to 40°) to 27° (range, -10° to 70°). A preoperative external rotation lag sign could be corrected in 25 of the 32 shoulders. For the 16 shoulders with at least 5 years of follow-up, the Constant scores were 47% (range, 16%-80%) preoperatively, 92% (range, 51%-100%) at 2 years, and 94% (range, 57%-100%) at the latest follow-up, and the respective subjective shoulder values were 32% (range, 0%-70%), 73% (range, 30%-100%), and 80% (range, 60%-100%).

CONCLUSION

If treated with RTSA combined with LDT, patients with pseudoparesis of elevation and pseudoparesis of external rotation can expect an excellent clinical outcome for a period beyond 5 years, provided that complications that require removal of the prosthesis can be prevented.

Reverse total shoulder arthroplasty in patients of varying body mass index

BACKGROUND

Body mass index (BMI) is an independent predictor of complications after hip and knee arthroplasty. Whether similar trends apply to patients undergoing reverse total shoulder arthroplasty (RTSA) is unknown.

METHODS

A retrospective review of primary RTSAs with a minimum 90-day follow-up were included. Complications were classified as major or minor and medical or surgical. Patients were classified into 3 groups: normal BMI (BMI <25 kg/m(2)), overweight or mildly obese (BMI 25-35 kg/m(2)), and moderately or severely obese (BMI >35 kg/m(2)).

RESULTS

Of the 119 patients met our inclusion criteria, 30 (25%) had a BMI of less than 25 kg/m(2); 65 (55%) had a BMI of 25 to 35 kg/m(2), and 24 (20%) had BMI exceeding 35 kg/m(2). Complications occurred in 30 patients (25%), comprising major in 11 (9%), minor in 19 (16%), surgical in 21 (18%), and medical in 14 (12%). The most common surgical complications were acute blood loss anemia requiring transfusion (8.4%) and dislocation (4.2%). The most common medical complications were atelectasis (2.5%) and acute renal insufficiency (2.5%). Patients with a BMI exceeding 35 kg/m(2) had a significantly higher overall complication rate (P < .05) and intraoperative blood loss (P = .05) than the other groups. Patients with BMI of less than 25 kg/m(2) had a greater overall complication rate than those with a BMI of 25 to 35 kg/m(2) (P < .05). Multivariate regression analysis demonstrated BMI was the only significant determinant of overall complication rates and medical complication rates (P < .05).

CONCLUSION

Patients with a BMI exceeding 35 kg/m(2) (severely obese) or a BMI of less than 25 kg/m(2) have higher rates of complication after RTSA.

Reverse shoulder arthroplasty for treatment of proximal humeral fractures in older adults: a systematic review

BACKGROUND

Displaced proximal humeral fractures have traditionally been treated with hemiarthroplasty in older adults, but sometimes hemiarthroplasty results in poor functional outcomes due to rotator cuff deficiency. Reverse shoulder arthroplasty (RSA) can offer potentially improved outcomes in these situations. We assessed the functional outcomes of older adults treated with RSA for proximal humeral fractures compared with hemiarthroplasty.

METHODS

We searched MEDLINE, the Cochrane Central Register of Controlled Trials, EMBASE, and 3 clinical trials registries. We included all studies treating proximal humeral fractures with RSA in adults with a mean age older than 60 years and 1 year of follow-up. We calculated weighted mean differences (WMD) for range of motion and standardized mean differences (SMD) for shoulder scores. Postoperative complications were evaluated qualitatively.

RESULTS

Fifteen studies met inclusion criteria, including 377 patients treated with RSA and 504 patients treated with hemiarthroplasty. In controlled studies, the RSA group had improved forward flexion (WMD, 21°;, P = .02) and functional outcome scores (SMD, 0.44; P = .005) compared with the hemiarthroplasty group but decreased external rotation (WMD, -5°; P < .0001). Postoperative complications were similar between the 2 groups.

CONCLUSION

RSA results in improved forward flexion and functional outcome scores compared with hemiarthroplasty for older adults with proximal humeral fractures. Complications do not appear to be appreciably higher in the RSA group in the existing follow-up. The results of this review suggest that RSA is a reasonable alternative for treating older adults with proximal humeral fractures, but more research and longer follow-up are needed.

LEVEL OF EVIDENCE

Level IV, systematic review.

Health-related quality of life and functionality after reverse shoulder arthroplasty

BACKGROUND

Modern semiconstrained reverse shoulder arthroplasty (RSA) has shown a great improvement in function and range of motion (ROM) in different etiologies, including revision surgery, sequelae of fractures, or tumors. Few studies have evaluated RSA for primary glenohumeral osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy excluding any other shoulder disease, and data on patients' quality of life after this surgery are lacking.

METHODS

In this prospective cohort study, 80 patients were evaluated after an RSA for either primary osteoarthritis, massive rotator cuff tear, or cuff tear arthropathy with the Constant-Murley score (CMS), ROM, and Short Form Health Survey (SF-36). A radiologic assessment was performed preoperatively and postoperatively in 62 of these patients.

RESULTS

At a mean 5-year follow-up, the cumulative survival rate was 97.3% and significant improvements in the CMS and ROM were observed when compared with the baseline values. The CMS was 93.2% of the sex- and age-matched normal values. The postoperative SF-36 scores showed no significant differences compared with normative data. Younger patients and subjects with worse preoperative conditions achieved the greatest benefit after RSA. The length of follow-up was found to be associated with the severity of scapular notching.

CONCLUSIONS

This study introduces new predictors for surgical outcomes, and it shows that patients who had undergone RSA a mean of 5 years earlier exhibit similar functionality and health-related quality of life with respect to healthy controls. Physicians should consider these results when discussing the outcomes of this surgery with patients.

LEVEL OF EVIDENCE

Level IV, Case series, treatment study.

Arm lengthening after reverse shoulder arthroplasty: a review

PURPOSE

The purpose of this review is to provide a better understanding of biomechanical changes induced by reverse shoulder arthroplasty (RSA), discuss the different techniques of radiographic assessment of upper limb lengthening after RSA and determine the ideal soft tissue tension that provides the best functional outcome without increasing the risk of complications.

METHODS

Inclusion criteria were articles in which the primary interest was the technique of measuring upper-extremity lengthening after complications related to lengthening and its role in postoperative function; those written in English, French or German; and those that provided evidence levels I-IV relevant to search terms.

RESULTS

Seven articles met our inclusion criteria. Postoperatively, changes in humeral length varied from minus five to five millimetres, and changes in upper-extremity length varied from 15 mm to 27 mm. The acromiohumeral distance averaged 23 mm. Humeral and arm shortening increased the risk of dislocation and led to poor anterior active elevation. The type of surgical approach did not play a role in postoperative function. Subclinical neurological lesions were frequent.

CONCLUSIONS

Studies in this systematic review indicate that deltoid tensioning by restoring humeral length and increasing the acromiohumeral distance is critical for adequate postoperative function and to prevent dislocation. Excessive arm lengthening should be avoided, with zero to two centimetres of lengthening being a reasonable goal to avoid postoperative neurological impairment.

[Indication for primary fracture prosthesis of the shoulder]

Although fractures of the proximal humerus are one of the most common osteoporotic fracture types, no generally accepted treatment algorithm exists in the current literature. For young patients with high functional demands and good rehabilitation potential, we recommend humeral head salvage therapy. If symptomatic humeral head necrosis occurs, the implantation of an anatomic endoprothesis is possible on a secondary basis. For patients with a biological age > 70 years suffering from a persisting defect of the rotator cuff along with a humeral head fracture or from a multiple fragment fracture of the humeral head, we increasingly prefer implantation of a reverse shoulder prosthesis due to good clinical results. However, because of technical aspects and a high complication rate, treatment using the reverse fracture prosthesis should be reserved for surgeons with expertise in this particular field. After analyzing the fracture- and patient-specific risk factors and performance expectations, the trauma surgeon can select the best individual therapy with the patient.

Initial glenoid fixation using two different reverse shoulder designs with an equivalent center of rotation in a low-density and high-density bone substitute

BACKGROUND

Numerous glenoid implant designs have been introduced into the global marketplace in recent years; however, little comparative biomechanical data exist to substantiate one design consideration over another.

MATERIALS AND METHODS

This study dynamically evaluated reverse shoulder glenoid baseplate fixation and compared the initial fixation associated with 2 reverse shoulder designs having an equivalent center of rotation in low-density and high-density bone substitute substrates.

RESULTS

Significant differences in fixation were observed between implant designs, where the circular-porous reverse shoulder was associated with approximately twice the micromotion per equivalent test than the oblong-grit-blasted design. Additionally, 6 of the 7 circular-porous reverse shoulders failed catastrophically in the low-density bone model at an average of 2603 ± 981 cycles. None of the oblong-grit-blasted designs failed in the low-or high-density bone models and none of the circular-porous designs failed in the high-density bone models after 10,000 cycles of loading.

CONCLUSION

These results demonstrate that significant differences in initial fixation exist between reverse shoulder implants having an equivalent center of rotation and suggest that design parameters, other than the position of the center of rotation, significantly affect fixation in low-density and high-density polyurethane bone substitutes. Subtle changes in glenoid baseplate design can dramatically affect fixation, particularly in low-density bone substitutes that are intended to simulate the bone quality of the recipient population for reverse shoulders.

Revision to reverse shoulder arthroplasty with retention of the humeral component

BACKGROUND

Revision in failed shoulder arthroplasty often requires removal of the humeral component with a significant risk of fracture and bone loss. Newer modular systems allow conversion from anatomic to reverse shoulder arthroplasty with retention of a well-fixed humeral stem. We report on a prospectively evaluated series of conversions from hemiarthroplasty to reverse shoulder arthroplasty.

METHODS

In 14 cases of failed hemiarthroplasty due to rotator cuff deficiency and painful pseudoparalysis (in 13 women), revision to reverse shoulder arthroplasty was performed between October 2006 and 2010, with retention of the humeral component using modular systems. Mean age at the time of operation was 70 (56-80) years. Pre- and postoperative evaluation followed a standardized protocol including Constant score, range of motion, and radiographic analysis. Mean follow-up time was 2.5 (2-5.5) years.

RESULTS

Mean Constant score improved from 9 (2-16) to 41 (17-74) points. Mean lengthening of the arm was 2.6 (0.9-4.7) cm without any neurological complications. One patient required revision due to infection.

INTERPRETATION

Modular systems allow retainment of a well-fixed humeral stem with good outcome. There is a risk of excessive humeral lengthening.

Revision surgery of reverse shoulder arthroplasty

BACKGROUND

There is limited knowledge regarding revision of reverse shoulder arthroplasty (RSA). This study assesses reasons for failure in RSA and evaluates the outcomes of revision RSA.

MATERIALS AND METHODS

Between 1997 and 2009, 37 patients with RSA had revision surgery. Clinical and radiologic examinations performed preoperatively and at 3 months, at 6 months, and then annually postoperatively were analyzed retrospectively. Patients were reviewed with a minimum 2-year follow-up.

RESULTS

The most common causes for RSA revision were prosthetic instability (48%); humeral loosening, derotation, or fracture (21%); and infection (19%). Only 2 patients (3%) had to be reoperated on for glenoid loosening. More than 1 re-intervention was performed in 11 patients (30%) because of recurrence of the same complication or appearance of a new complication. Underestimation of humeral shortening and excessive medialization were common causes of recurrent prosthetic instability. Proximal humeral bone loss was found to be a cause for humeral loosening or derotation. Previous surgery was found as a potential cause of low-grade infection. At a mean follow-up of 34 months, 32 patients (86%) had retained the RSA whereas 2 patients (6%) had undergone conversion to humeral hemiarthroplasty and 3 (8%) to a resection arthroplasty. The mean Constant score in patients who retained the RSA increased from 19 points before revision to 47 points at last follow-up (P < .001).

CONCLUSIONS

Even if revision may lead to several procedures in the same patient, preservation or replacement of the RSA is largely possible, allowing for a functional shoulder. Full-length scaled radiographs of both humeri are recommended to properly assess humeral shortening and excessive medialization before revision.

Reverse shoulder arthroplasty - a literature review

Professor Grammont revolutionised shoulder surgery with his reverse shoulder arthroplasty design. Patients who had poor results from a conventional shoulder replacement because of cuff deficiency can now be treated effectively. Although designed for cuff tear arthropathy, indications continue to evolve and broaden. The initial results look very promising and the implant has gained much popularity over the years. The article provides an extensive literature review of the indications, results and complications for reverse shoulder arthroplasty.

Results of a stemless reverse shoulder prosthesis at more than 58 months mean without loosening

HYPOTHESIS

A stemless reverse shoulder prosthesis with humeral cup was developed to allow stemless press-fit fixation, to preserve bone stock. Our hypothesis was that a stemless reverse shoulder arthroplasty could produce the same functional results without compromising humeral fixation.

METHODS

This is a continuous, prospective, single-surgeon series including prostheses implanted from 2004 to 2009. Patients received pre- and postoperative clinical evaluation with measurement of joint mobility, the Oxford Shoulder score, and the Constant-Murley score by independent evaluators. Standard radiographs and computed tomographic arthrography were performed.

RESULTS

Fifty-six implants were reviewed at a mean of 58 months (38-95). The Constant-Murley score improved from 29 to 62 points and the Oxford Shoulder score from 46 to 17 points. Active elevation in forward flexion improved from 79° to 140°. One intraoperative complication was recorded: a metaphyseal-diaphyseal humeral bone crack without consequence. One revision surgery due to early instability was performed using a conventional implant. No humeral loosening was observed. Five cases of scapular notching were reported.

CONCLUSION

This is the first study reporting results with mid-term follow-up for a stemless reverse shoulder arthroplasty. The clinical results are comparable to conventional prostheses with stem. The absence of a humeral stem preserves bone stock for possible later revisions.

Reverse total shoulder arthroplasty for massive irreparable rotator cuff tears in patients younger than 65 years old: results after five to fifteen years

BACKGROUND

The role of reverse shoulder arthroplasty (RTSA) in the relatively young individual is currently unclear. Our study evaluates the midterm to long-term results of RTSA for patients aged younger than 65 years with pseudoparalysis secondary to massive irreparable rotator cuff tears, with or without arthritis.

METHODS

Between 1997 and 2006, 46 RTSAs (41 patients) were performed. Mean age was 60 years (range, 46-64 years). At the latest follow-up, 5 patients had died and 1 was lost, leaving 35 patients (40 shoulders) with a mean follow-up of 93 months (range, 60-171 months).

RESULTS

The mean relative Constant score increased from 34% to 74% (P < .0001) and the subjective shoulder value improved from 23% to 66% (P < .0001). Significant improvements were seen in active forward elevation (72° to 119°), pain scores, and strength (P < .001). One or more complications occurred in 15 shoulders (37.5%), with 6 failures (15%) resulting in removal or conversion to hemiarthroplasty (3 with infection, 3 with glenoid loosening). Ten shoulders (25%) underwent partial or total component exchange, conversion to hemiarthroplasty, or removal. Of the 15 patients who developed complications, 9 did not require prosthesis removal or conversion and functional outcome and subjective shoulder value were similar to those with no complications (P > .4).

CONCLUSION

RTSA in younger patients provides significant subjective improvement and substantial gain in overall function, which is maintained up to 10 years. Although the complication rate is high, most can be treated successfully without compromise to clinical outcome. However, it is imperative that the high complication rate is explained to patients, with the risks and benefits carefully considered.

The impact of scapular notching on reverse shoulder glenoid fixation

BACKGROUND

Scapular notching is a well-documented complication of reverse shoulder arthroplasty. The effect of scapular notching on glenoid fixation is unknown.

MATERIALS AND METHODS

This study dynamically evaluated reverse shoulder glenoid baseplate fixation and assessed the effect of scapular notching on fixation in composite scapulae. A cyclic test was conducted to simulate 55° of humeral abduction in the scapular plane as a 750-N axial load was continuously applied to induce a variable shear and compressive load. Before and after cyclic loading, a displacement test was conducted to measure glenoid baseplate displacement in the directions of the applied static shear and compressive loads.

RESULTS

For the scapulae without a scapular notch, glenoid baseplate displacement did not exceed the generally accepted 150-μm threshold for osseous integration before or after cyclic loading in any component tested. For the scapulae with a scapular notch, glenoid baseplate displacement exceeded 150 μm in 2 of the 7 samples before cyclic loading and in 3 of the 7 samples after cyclic loading. The average pre-cyclic glenoid baseplate displacement in the direction of the shear load was significantly greater in scapulae with a scapular notch than those without a scapular notch both before (P = .003) and after (P = .023) cyclic loading.

CONCLUSIONS

Adequate glenoid baseplate fixation was achievable in most cases in scapulae with a severe scapular notch; however, the fact that this micromotion threshold was not met in all scapulae with a notch is concerning and implies that severe notching may play a role in initial glenoid baseplate stability.

Stress analysis of glenoid component in design of reverse shoulder prosthesis using finite element method

BACKGROUND

This study aims to clarify the effect of various designs of reverse shoulder prosthesis (RSP) on stress variation of its glenoid component using 2-dimensional (2D) finite element analysis (FEA). This FEA study provides future reference for the optimal design of glenoid component of RSP.

MATERIALS AND METHODS

In this study, a 2D finite element (FE) model of human shoulder with implementation of RSP was developed by commercial FE software. The proper material properties were adopted in our model. Various design factors were simulated and all the mechanical profile data were investigated by FEA.

RESULTS

Both distal placement and increased lateral offset of glenosphere induce higher stress over glenoid-baseplate junction. Increased thickness of graft, inferiorly tilting of the baseplate, and adoption of BIO-RSA (bony increased-offset reverse shoulder arthroplasty) incur higher stresses over glenoid screws. The inferior screw attains more stress than superior screw. Maximum stress occurs at the base of inferior screw.

CONCLUSION

Increased eccentric offset and lateral offset of glenosphere, although being able to reduce notching, may pay the penalty of significant stress concentration over glenoid and its subsequent loosening. Maximum stress occurs at the base of inferior screw elucidate the direct contact failure mode at the middle of inferior screw. This study provides an alternative tool for the optimal design of glenoid component of RSP in the future.

The use of an eccentric glenosphere compared with a concentric glenosphere in reverse total shoulder arthroplasty: two-year minimum follow-up results

PURPOSE

The current models of reverse shoulder arthroplasty (RSA) expose the procedure to the risk of scapular notching, possibly leading to loosening of the glenoid. We compared the clinical and radiographic results obtained with a concentric or eccentric glenosphere to assess whether the eccentric design might give better clinical results and avoid or decrease the risk of scapular notching

METHODS

Of our patients, 31 underwent RSA using a concentric glenosphere (group A), while 29 had an eccentric glenosphere (group B). Postoperatively, patients were followed-up at one to 12 months and annually thereafter, with the mean being 33 months in group A and 27.5 in group B. In both groups the minimum follow up (F-U) was 24 months. Preoperatively and at each F-U starting from six months, patients were assessed using the Constant score. On radiographs, prosthesis scapular neck angle (PSNA), distance between scapular neck and glenosphere (DBSNG) and peg-glenoid rim distance (PGRD) were calculated. The severity of notching was classified in four grades.

RESULTS

In group A the mean Constant score increased by 30 points compared to the preoperative score and the active ROM increased considerably. At latest F-U, the mean PSNA, DBSNG and PGRD were, respectively, 87°, 3.4 mm and 19.8 mm. Glenoid notching was present in 42% of cases. In group A, the mean Constant score increased by 34 points and the mean ROM was better than in group A. The average PSNA, PGRD and DBSNG were, respectively, 92°, 21.2 mm and 4.3 mm. Radiographs showed no inferior scapular notching.

CONCLUSIONS

The eccentric glenosphere yielded better clinical results than the concentric glenosphere and was associated with no scapular notching.

Reverse shoulder arthroplasty in acute fractures of the proximal humerus: A systematic review

The indications for surgical intervention in complex fractures of the proximal humerus are disputed. In elderly patients with poor bone stock it may be impossible to obtain satisfactory fixation of the tuberosities to a hemiarthroplasty (HA). In such cases primary insertion of a reverse shoulder arthroplasty (RSA) has been suggested. We aimed to review clinical studies reporting benefits and harms of RSA in acute fractures. A systematic review. We included 18 studies containing 430 RSA in acute fractures. We found no randomized clinical trials. Four studies compared outcome after RSA with a historical control group of HA. The median constant score was 58 (range 44-68) which is comparable to previous reviews of HA in 4-part fractures. Complications included dislocation, infection, hematoma, instability, neurological injury, reflex sympathetic dystrophy, intraoperative fractures, periprosthetic fractures, and baseplate failure. Scapular notching was reported in 11 studies with a median value of 25% (range 0-94). Heterogeneity of study designs and lack of primary data precluded statistical pooling of data. No high quality evidence was identified. Based on the available evidence the use of RSA in acute fractures is questionable. The complication rate was high and the clinical implications of long term scapular notching are worrying. Randomized studies with long term follow up using the latest techniques of tubercular reinsertion in RSA toward HA should be encouraged.

Factors affecting the stability of reverse shoulder arthroplasty: a biomechanical study

BACKGROUND

Despite the success of reverse shoulder arthroplasty (RSA) in treating patients with painful pseudoparalytic shoulders, instability is a common complication and currently the factors affecting stability are not well understood. The objective of this study was to investigate a number of factors as well as the interactions between factors to determine how they affect the stability of the prosthesis. These factors included: active arm posture (abduction and abduction plane angles), loading direction, glenosphere diameter and eccentricity, and humeral socket constraint.

METHODS

Force required to dislocate the joint, determined using a biomechanical shoulder simulator, was used as a measure of stability. A factorial design experiment was implemented to examine the factors and interactions.

RESULTS

Actively increasing the abduction angle by 15° leads to a 30% increase in stability and use of an inferior-offset rather than a centered glenosphere improved stability by 17%. Use of a more constrained humeral socket also increased stability; but the effect was dependent on loading direction, with a 88% improvement for superior loading, 66% for posterior, 36% for anterior, and no change for inferior loading. Abduction plane angle and glenosphere diameter had no effect on stability.

CONCLUSION

Increased glenohumeral abduction and the use of an inferior-offset glenosphere were found to increase the stability of RSA. Additionally, use of a more constrained humeral socket increased stability for anterior, posterior, and superior loading. These identified factor effects have the potential to decrease the risk of dislocation following RSA.

Duocentric® reversed shoulder prosthesis and Personal Fit® templates: innovative strategies to optimize prosthesis positioning and prevent scapular notching

We describe our experience with a new system of patient-specific template called Personal Fit(®), which is unique in shoulder surgery and used in combination with Duocentric(®) prosthesis. The reverse prosthesis's concept is the invention of Paul Grammont, developed with Grammont's team of Dijon University as from 1981, which led to the first reversed total shoulder prosthesis called Trumpet in 1985. The Duocentric(®) prosthesis developed in 2001 is the third-generation prosthesis, coming from the Trumpet and the second-generation prosthesis Delta(®) (DePuy). This prosthesis provides a novel solution to the notching problem with an inferior overhang integrated onto the glenoid baseplate. Personal Fit(®) system is based on reconstructing the shoulder joint bones in three dimensions using CT scan data, placing a landmark on the scapula and locating points on the glenoid and humerus. That will be used as a reference for the patient-specific templates. We study the glenoid position planned with Personal Fit(®) software relative to native glenoid position in 30 cases. On average, the difference between the planned retroversion (or anteversion in one case) and native retroversion was 8.6°.

The diagnostic protocol for evaluation of periprosthetic joint infection

Infection is becoming the most important as well as the most devastating mechanism of prosthetic joint failure. The incidence is increasing because the absolute number of patients operated is increasing and because more often very sick, debilitated and immunocompromised patients are operated. The trend reveals a further increase in the years to come. Diagnosis may be very easy in case of high grade processes, but also extremely difficult in some other instances. Misdiagnosing infection leads to repeated early failures that are distressing for patients as well as surgeons. To avoid failures related to misdiagnosed prosthetic joint infections a step-wise algorithm of action is proposed and the diagnostic strength of the steps discussed. The key point is to select potential candidates to define the probability of an ongoing infection and then to select the tools to strengthen the suspicion. Further procedures are based on the analysis of the pseudo-synovial fluid obtained by aspiration. Diagnostic conclusions form the basis for treatment decisions.

Revision of total shoulder arthroplasty

In France, the number of revisions for total shoulder arthroplasty (TSA) has increased by 29% between 2006 and 2010. Published studies have reported a revision rate of approximately 11% for hemi-arthroplasty and total anatomical implants, and 10% for reversed implants. The decision to revise or not revise a TSA requires that a rigorous, clinical, laboratory and imaging initial assessment be done in order to answer five questions. Is it infected? Is it unstable? Is it worn? Is it loosened? How is the rotator cuff? This assessment and an evaluation of the bone stock are required to decide whether or not to revise. If the problem is infection, the best solution is not always complete removal of the implant, which results in very poor shoulder function. In such a situation, a multidisciplinary consultation is essential in the decision-making. If the problem is instability, the cause must be identified and rectified. Instability is often caused by insufficient restoration of the humerus length. If the problem is loosening, the type of revision must take into account the patient's age, the rotator cuff status and the available bone stock. The possibilities to reimplant an anatomical glenoid are scarce, and only for cases with minor bone loss and an intact cuff. If a bone graft without reimplantation of a glenoid component is preferred, it should be a tricortical graft to resist wear and medialisation. In the other cases, a reversed shoulder implant with an autograft is preferable. Whether or not the humeral stem is loose, it must often be removed. However, its removal is very difficult, risky and it often causes complications, with humerus fracture being the most common. The possibility of reconstruction depends on the quality of the remaining bone stock. In all these risky situations, the patient should be duly informed and should take part in the decision-making process.

Evaluation of a reconstruction reverse shoulder for tumour surgery and tribological comparision with an anatomical shoulder arthroplasty

PURPOSE

The functional results after reconstruction of the proximal humerus in tumour surgery are poor. Therefore, a reversed proximal humerus replacement was developed in our institution (MUTARS humerus inverse). A low degree of wear on the polyethylene is required because of the patients' youth and demands on shoulder function. A special type of polyethylene with shock-absorbing properties has been developed to minimise polyethylene wear in the MUTARS inverse proximal humerus replacement. We compared the tribological properties of an anatomical shoulder prosthesis (CAPICA) with the new reversed proximal humerus replacement (MUTARS humerus inverse).

METHODS

Both prostheses were tested up to 5 × 10(6) cycles. Every millionth cycle the surface was inspected and a gravimetric measurement was performed. A measurement of surface roughness was done before testing and after 5 × 10(6) cycles.

RESULTS

In both prostheses after 5 × 10(6) cycles there were no major defects, such as delamination, observed. In the reversed proximal humerus replacement abrasion of 28 mg/10(6) cycles was detected. The mean abrasion of the anatomical prosthesis was 9.28 mg/ 10(6) cycles.

CONCLUSION

The glenoid component of the first reversed humerus replacement (MUTARS humerus inverse) has wear properties comparable to those of normal reversed shoulder prostheses. This is important, as this type of prosthesis is used in young patients after resection of bone tumours, with a good functional outcome. It can, therefore, be expected that the revision rate due to wear will be as high as in patients with normal reversed shoulder prostheses.

Reverse total shoulder arthroplasty: early results of forty-one cases and a review of the literature

Reverse total shoulder arthroplasty was officially approved for use in the United States in 2003. The procedure is proving to be one of the most exciting advances in upper extremity surgery in the past quarter-century. The prosthesis is used to salvage the arthritic, unstable, rotator cuff-deficient shoulder and allow patients to obtain nearly pain-free overhead motion of the upper limb. This article reviews the previous literature and the results of 41 reverse shoulder arthroplasties implanted in 39 patients by a single orthopedically trained hand and upper extremity surgeon at a single institution from November 2004 until July 2011.

Total shoulder arthroplasty for the treatment of failed hemiarthroplasty in patients with fracture of the proximal humerus

BACKGROUND

Little information is available for the outcomes of conversion to total shoulder arthroplasty (TSA) of failed hemiarthroplasty (HA) implanted for fractures or fracture-dislocations of the proximal humerus.

MATERIALS AND METHODS

We evaluated the clinical and radiographic results in 16 patients who underwent conversion of HA to TSA due to pain and shoulder disfunction. Patients were a mean age of 63 years at revision, which was occurred a mean of 3.3 years after the HA. The main prerequisites for conversion were forward flexion to at least 60°, no massive cuff tear, or severe resorption or nonunion of the tuberosities. In all cases, a modular prosthesis was used in the HA, uncemented in 14 and cemented in 2. The latest follow-up was a mean of 4.6 years after revision.

RESULTS

The mean Constant score was 50.6 (range, 33-69), with an average increase of 11.9 points compared with the preoperative score (P = .001). In 75% of patients, the mean score was 54.6 (average increase, 15.1 points). The lowest scores occurred in patients with a cemented prosthesis that needed to be removed, and in 1 patient who had loosening of the implanted glenoid that was revised.

CONCLUSIONS

Conversion of HA to TSA can improve the preoperative condition in most patients aged in their 50s or 60s in the absence of rotator cuff deficiency and severe bone loss of the proximal humerus.

Patient reported activities after reverse shoulder arthroplasty: part II

BACKGROUND

Reverse shoulder arthroplasty (RSA) is becoming a commonly performed procedure. Surgeons are advised to select older patients with lower demands. This study defines patient reported activities following RSA.

MATERIALS AND METHODS

Seventy-eight patients with 81 treated shoulders (average age 73 years; 49 women, 32 men) completed a survey asking about clinical parameters: pain, motion, strength, and 72 different activities. Diagnoses were rotator cuff tear arthropathy in 70 shoulders, massive rotator cuff tears with psuedoparalysis in 6, and failed treatment for proximal humeral fractures in 5. Average time from surgery to survey was 3.6 years (range, 3-5).

RESULTS

All clinical parameters were favorable. The 3 most commonly reported activities were low demand (cooking, baking, and driving), medium demand (gardening, leaf raking, and lawn mowing), and high demand (snow shoveling, wheelbarrow use, and dirt shoveling). These were comparable to the activities reported for total shoulder arthroplasty and hemiarthroplasty. There was no clinical or activity difference between those components with a lateral or a medial center of rotation.

CONCLUSION

A significant proportion of patients continue medium or high demand activities following RSA. These are similar to other types of shoulder arthroplasties. Future studies to determine the safety level of different activities would be helpful to counsel patients accordingly.

Do the indications, results, and complications of reverse shoulder arthroplasty change with surgeon's experience?

BACKGROUND

The goal of this study was to compare 2 consecutive series of 240 reverse total shoulder arthroplasties (TSA) in order to evaluate if the increase in surgeon experience modified the indications, clinical and radiographic results, and rate of complications.

MATERIAL AND METHODS

Two hundred forty reverse TSA performed between July 2003 and March 2007 were clinically and radiographically evaluated by an independent examiner with a minimum follow-up of 2 years and compared with a previous published study (240 cases implanted by the same 2 surgeons between May 1995 and June 2003).

RESULTS

The main etiology remained cuff tear arthropathy with an increase noted between the 2 studies. The rate of revision arthroplasty as an etiology decreased from 22.5% to 9.1%. Conversely, the rate of rheumatoid arthritis increased from 0.4% to 6.3%. The average postoperative Constant score was significantly better than the first series (66.9 vs 59.7, P < .001). The postoperative complication rate decreased with increased experience (from 19% to 10.8%), with dislocations reducing (from 7% to 3.2%), and infections reducing (from 4% to 0.9%). However, the number of nerve palsies increased. The revision rate decreased from 7.5% to 5%. The rate of glenoid notching remained stable, but the severity of notching decreased.

CONCLUSION

Experience did not lead us to operate on younger patients, but significantly modified patient selection, results, and complications. Increased experience with the reverse shoulder arthroplasty did not reduce the rate of glenoid notching.

A review of shoulder replacement surgery

Shoulder replacement surgery is employed in the treatment of severe shoulder arthritis and following some proximal humeral fractures. Three different replacements are available: hemiarthroplasty (HAS), total shoulder replacement (TSR) and reverse shoulder replacement (RSR). HAS and TSR are indicated in patients with intact rotator cuffs and RSR for cuff deficient older patients. Outcomes are favourable, with the majority of patients having improvements in shoulder pain and function.

Shoulder function and pain level after revision of failed reverse shoulder replacement to hemiarthroplasty

BACKGROUND

The reverse total shoulder replacement has become a popular treatment option for cuff tear arthropathy and other shoulder conditions requiring arthroplasty in the setting of a deficient rotator cuff. Despite a revision rate of as much as 10%, to date, there are few reports of reverse replacement conversion to hemiarthroplasty, and none specifically examining shoulder function.

MATERIALS AND METHODS

Six patients with a reverse replacement that was dislocated, infected or loose were revised an average of 9.2 months after the reverse replacement. Two of the three patients that were dislocated also had a known deep infection. Patients with known infection were treated with explant of the reverse prosthesis and conversion to a preformed antibiotic spacer hemiarthroplasty. In three cases with gross loosening of the glenosphere without infection, treatment was performed with removal of glenosphere only, bone grafting of glenoid with allograft and conversion of humeral stem to hemiarthroplasty. Patients were evaluated with outcome scores and physical examination an average of 26.5 months after removal of the reverse prosthesis.

RESULTS

The average range of motion postoperatively was forward elevation 42.5 degrees and external rotation 1.7 degrees. The VAS pain score was 2.42 (range 0-6); simple shoulder test was 3.17 (range 1-5); and ASES score was 52.1 ± 8.5. There were no reoperations to date, and five patients had anterosuperior escape.

CONCLUSIONS

Safe removal of a reverse replacement and conversion to hemicement spacer or hemiarthroplasty can provide pain relief in those patients with a dislocated or infected reverse replacement. However, the shoulder will likely have very poor function and anterosuperior escape postoperatively. Further studies are needed to determine the optimal treatment for the failed reverse shoulder replacement.

LEVEL OF EVIDENCE

Therapeutic Level IV.

Total shoulder arthroplasty - arthroplasty for glenohumeral arthropathies: results and complications after a minimum follow-up of 8 years according to the type of arthroplasty and etiology

INTRODUCTION

Arthroplasty for glenohumeral arthropathies have specific complications and the final results are sometimes more dependent upon the type of shoulder arthroplasty than the initial etiology. The aim of our study was to evaluate the rate of complications and the functional improvement with different types of shoulder arthroplasties after a minimum follow-up of 8 years.

MATERIALS AND METHODS

This was a multicenter retrospective study of 198 shoulders including 85 primary osteoarthritis of the shoulder, 76 cuff tear arthropathies, 19 avascular necrosis and 18 rheumatoid arthritis. Arthroplasties included 104 anatomic total shoulder arthroplasties (TSA), 77 reverse arthroplasties and 17 hemiarthroplasties. Ten patients had their arthroplasty revised, and 134 patients with TSA were able to be present at the final follow-up or provide information on their case. Function was evaluated by the Constant-Murley score and loosening by standard radiographs.

RESULTS

In the group with primary osteoarthritis of the shoulder, there were eight complications (11%) including six (8.3%) requiring implant revision. In the group of rotator cuff arthropathies, there were nine (14.7%) complications including four (6.5%) requiring implant revision. In the group with rheumatoid arthritis, there was one complication, and no surgical revision was necessary. There were no complications in the group with avascular necrosis. Glenoid migration occurred in 28.5% of anatomic TSA, and 3.4% of reverse arthroplasties. This difference was significant (P<0.001). The Constant-Murley score was significantly improved in all etiologies.

CONCLUSIONS

Glenohumeral arthropathies can be successfully treated by arthroplasty. Anatomic TSA was shown to be associated with a high risk of glenoid loosening at radiographic follow-up, which makes us hesitate to use the cemented polyethylene implant, especially in young patients.

LEVEL OF EVIDENCE

IV - Retrospective study.

Hemiarthroplasty versus reverse total shoulder arthroplasty for acute proximal humerus fractures in elderly patients

Proximal humerus fractures are the third most common fracture in elderly patients. Hemiarthroplasty has been the treatment of choice in patients with bone quality and fracture patterns not amenable to open reduction and internal fixation. Reverse total shoulder arthroplasty is a newer option that appears to be less dependent on tuberosity healing than hemiarthroplasty. The authors hypothesized that reverse total shoulder arthroplasty provides improved functional outcomes compared with hemiarthroplasty for fractures in elderly patients.A retrospective review was performed of all patients treated with arthroplasty for acute proximal humerus fractures in an orthopedic practice using a Current Procedural Terminology code search, patient charts, and radiographs. Validated outcome scores were used to assess satisfaction, function, and general well-being. Twenty-three patients were treated for acute proximal humerus fractures (11 reverse total shoulder arthroplasties and 12 hemiarthroplasties). Three patients were lost to follow-up, and 6 patients were deceased. Mean follow-up was 3.6 years (range, 1.3-8 years). Reverse total shoulder arthroplasty outperformed hemiarthroplasty with regard to forward flexion, American Shoulder and Elbow Society score, University of Pennsylvania shoulder score, and Single Assessment Numerical Evaluation score.Reverse total shoulder arthroplasty is a reliable option for acute, proximal humerus fractures that are not amenable to closed treatment or reconstruction in elderly patients. Improved functional outcomes when compared with hemiarthroplasty must be balanced against the increased cost and limited life expectancy of patients with this injury.

Glenoid loosening and failure in anatomical total shoulder arthroplasty: is revision with a reverse shoulder arthroplasty a reliable option?

INTRODUCTION

Our purpose was to evaluate if, in case of aseptic glenoid loosening and failure in anatomical total shoulder arthroplasty (TSA), revision by a reverse shoulder arthroplasty (RSA) is a reliable therapeutic option.

METHODS

Retrospective multicenter cohort study of 37 consecutive anatomical TSA revised by RSA for aseptic glenoid loosening or failure. The decision to implant a RSA was related to the presence of associated complications: rotator cuff tears (n = 24), subscapularis insufficiency (n = 29), prosthetic instability (n = 13), and glenoid bone deficiency (n = 37). The patients were reviewed clinically and radiographically at a mean follow-up of 47 months (range, 24-104).

RESULTS

Eighty-six percent of the patients were satisfied or very satisfied. The average Constant score increased from 24 to 55 pts (P < .0001) and active anterior elevation from 68° to 121° (P < .0001). Twenty-two of the 29 (76%) associated bone grafts were incorporated in the glenoid. Eight patients (21%) needed a subsequent reoperation because of recurrent or new complications: glenoid loosening (n = 3), prosthetic anterior instability (n = 3), and humeral subsidence (n = 2); the reverse prosthesis had to be converted to a hemiarthroplasty in 1 patient and removed in another.

CONCLUSION

Revision with a RSA is a reliable therapeutic option which provides the double benefit of glenoid bone stock reconstruction by fixing the bone graft with the help of the baseplate and screws and of solving the problem of soft tissue insufficiency and prosthetic instability. However, surgeons should be aware that the rate of postoperative complications and subsequent reoperations is high, and that the surgical technique is demanding.

Reverse shoulder arthroplasty

The reverse shoulder arthroplasty emerged as a potential solution for those patients who could not be managed effectively with a conventional total shoulder arthroplasty. Grammont revolutionized the design by medializing and distalizing the center of rotation and utilizing a large convex glenoid surface and concave humeral component with a neck-shaft angle of 155°. This design has been highly successful in cuff deficient shoulders, and indications continue to broaden. Many mid-term studies have improved upon the early encouraging results. Long-term studies are starting to emerge, demonstrating good survivorship, but progressive functional and radiographic deterioration continue to be concerning. Careful patient selection and attention to appropriate technique are required to reduce the current high rate of complications. New prosthesis designs are continuing to develop to address some of these limitations.