Results after Arthroplasty

Green and Norri [62] retrospectively evaluated 17 of 19 patients with shoulder prosthesis (15 TSA and two HSA) due to dislocation arthropathy (four Bristow, four Putti Platt, four Magnuson Stack, two Bankart, and four soft tissue operations) after 62 months; 94% had significant pain relief. Except for one, all patients received a better function. Subjectively, 16 patients judged the result as much better or better and one as worse. Three patients had to be revised.

Sperling et al. examined 31 patients (21 TSA, 10 HSA) retrospectively for at least two years and an average of 7 years postoperatively [67]. Pain, external rotation, and active abduction improved significantly without differences between HSA and TSA. The survival rate after two years was 97%, after five years 86%, and after ten years, only 61%. Nevertheless, 3/10 HSA and 8/21 TSA had to be revised.

Hill and Norris examined the results after bony glenoid reconstruction at five anterior and 12 posterior defects, five patients with arthrosis, three with capsulorrhaphy arthropathy, two with recurrent dislocations, and one after revision. All had a certain anterior or posterior instability preoperatively [68]. In 15 patients, a bone from the resected humeral head was used. The indication for transplantation of a bone graft existed, if the bone substance was not sufficient to correct the version (version >15◦), to ensure the fixation of the glenoidal component (withdraw the keel when planning), or if via a version of the components no adjustment could be made. After correction, an average retroversion of 4◦ with an average correction angle of 33◦ could be seen. Three patients with graft failure (nonunion, dissolution, or graft dislocation) and five failures with glenoid revisions because

of rotator cuff rupture, persisting instability, wrong component placement, or loosening of the transplant, showing unsatisfactory functional results. In 14 of 17 cases, the version and substance of the glenoid could be repaired. The patients without implant or transplant failure showed an apparent reduction in pain and good gain of function (AAE on average 107◦ (30–165◦), i.e., satisfying functional results in nine of 17 patients. The study of Neer showed a lower failure rate (0 of 19) [66].

**Figure 5.** 22-year-old patient with dislocation arthropathy after instability surgery treated with stemless prosthesis. **First row**: radiographs showing OA after shoulder instability surgery. **Second row**: intraoperative pictures of hemiprosthesis. **Third row**: Physical examination and shoulder function at final follow-up.

**Figure 6.** 61-year-old male with bilateral dislocation arthropathy. (**A**): right shoulder dislocation arthropathy after instability surgery. (**B**): left shoulder dislocation arthropathy after instability surgery. (**C**): treatment with bilateral two surgeries Reverse Shoulder Arthroplasty using full wedge. (**D**): right side 12 months follow up and left side 6 months follow up clinical results.

Primary glenoidal bone graft transplantation has a ten times higher risk of glenoidal failure than patients with primary implantation without bone transplantation. If the transplant heals sufficiently, there is no tendency for early loosening. The transplantation is suitable to lower the post-operational instability rate [68].

Matsoukis et al. examined two collectives in a multicentric study, one with and one without previous stabilization operation [69]. Twenty-eight patients without preceding operations had been seen at least for two years. One group sustained the first dislocation under and the other one over the age of 40 years. Below 40 years, the processes were longer, and there were numerous recurrences, but only one rotator cuff tear was found; 64% had an excellent or good result, similar to concentric osteoarthritis. The processes were short in the second group with patients older than 40 years. With seven rotator cuff tears, only 36% of them had an excellent or good result. Because of the rotator cuff tears, hemiprostheses had been implanted in most cases. The difference is probably due to the higher rate of rotator cuff tears.

In contrast to fatty degeneration of the rotator cuff, especially of the subscapularis muscle, the preceding operation and the preoperative external rotation did not influence the result. Altogether, prosthetics could achieve good results due to dislocation arthropathy after conservative and operational treatment. Significantly better results were shown after TSA than HSA. Adverse prognostic factors were a higher age at the initial dislocation and a rotator cuff tear. The previous surgery, e.g., bone block or soft part operation, was without significant influence (10 complications in 55 prostheses, three cases of glenoid loosening in connection with rotator cuff ruptures, four anterior instabilities, six revisions) [70]. Lehmann et al. report a significantly increased weighted average constant score following shoulder arthroplasty for OA caused by shoulder instability [63]. The authors found no significant difference between total shoulder replacements and hemiarthroplasty. Nevertheless, a relatively high rate of complications (40%) was revealed, with 20% requiring an operative revision.

Due to inconsistent results, surgeons are moving towards the implantation of RSA after dislocation arthropathy (Figure 6). There is a trend of positive results with these implants, ye<sup>t</sup> follow-up is still relatively short. RSA has been used in recent years for patients with OA and rotator cuff deficiency after shoulder stabilization. Raiss et al. describe the results of 13 patients with a median follow-up of 3.5 years and a median age of 70 years that had at least one rotator cuff tendon tear in combination with an OA treated before for recurrent anterior shoulder instability. Constant score, shoulder flexion, and internal rotation significantly improved after RSA and were comparable with those of other studies reporting on the outcome of reverse shoulder arthroplasty for other conditions [71].

For Clavert et al., RSA is justified due to the higher rate of complications and revisions of non-constrained anatomic shoulder arthroplasties reported. In his cohort of 25 patients with a mean follow-up of 6.6 years, clinical results were comparable to other studies describing results of RSA, even in cases where bone grafting was mandatory [72]. Besides satisfactory clinical and radiological results have been published, and follow-up is still relatively short for this indication.
