Introduction: Clinically evident neurological injury of the operated limb after total shoulder arthroplasty is not uncommon. The purpose of this prospective study was to determine the incidence of subclinical neurological lesions after reverse shoulder arthroplasty and anatomic shoulder arthroplasty (group control), and to correlate its occurrence to postoperative lengthening of the arm.

Method: We included all patients needing a total shoulder arthroplasty either anatomic or reversed. Each patient underwent a pre- and postoperative electromyography (EMG). This study focused on the clinical, radiological and EMG evaluation, with a measure of the lengthening of the arm in case of reversed shoulder arthroplasty according to a protocol previously validated.

Result: Between November 2007 and February 2009, we collected 41 patients (42 prostheses), including 23 anatomic (group 1) and 19 reverse (group 2) primary shoulder arthroplasties. The 2 groups were similar according to mean age, comorbidity, male/female ratio and nerve conduction abnormalities on EMG performed on an average of 10 days before surgery. Control EMG realized at an average of 3.6 weeks postoperatively showed in group 1, a plexus lesion due to an intra-operative complication. In group 2, we noticed 9 recent neurological damages (45% of cases) involving mainly the axillary nerve; 8 were rapidly regressive. The incidence of recent injury was significantly more frequent in group 2 (p=0.003) with a risk 10.4 times higher (95% CI 1.4, 74.8). Mean lengthening of the arm after a reverse was 3.1 cm ± 1.8 (range 0.2 to 5.9) compared to preoperative measurement and 2.4 cm ± 2.1 (range −0.5 to 5.8) compared with the normal contra-lateral side.

Discussion: The occurrence of peripheral neurological lesion following a reverse shoulder arthroplasty is common but usually transient. These lesions may cause postoperative pain, alter rehabilitation and can theoretically induce prosthetic instability. Lengthening of the arm is considered as one of the major factors responsible for this neurologic damage. Indeed, surgical dissection, compression phenomena by use of retractors or presence of hematoma, vascular injury, mobilization of the upper limb and possibly interscalene block are similar for the two types of prosthesis. Arm lengthening is thus a compromise between necessary retensionning of the deltoid for good mobility and instability avoidance, and lengthening which may be responsible for neurological lesions, acromial fractures and permanent arm abduction.

Purpose of the study: Revision total hip arthroplasty (rTHA) is associated with higher mortality than primary total hip arthroplasty (pTHA). The functional outcome after rTHA is globally satisfactory but less so than with primary implantation. Nevertheless, data are scarce. Patients undergoing revision procedures are older and have more co-morbid conditions. In this context, we evaluated quality-of-life and patient satisfaction five years after implantation, comparing rTHA versus pTHA. We analyzed the impact of age, obesity, and co-morbid conditions.

Material and methods: The study cohort included all patients undergoing pTHA (n=471) OR rTHA (n=124) in our unit between 1996 and 2000. Five years postoperatively, we noted the Harris hip score (HHS) and patient satisfaction, assessed on a visual analog scale (VAS) from 1 to 10.

Results: The rTHA patients were older (72 yeras versus 68 years, p=0.004), more frequently obese (BMI30: 33% versus 19%, p=0.003) and presented more co-morbid conditions involving medical ( 2: 46% versus 21%, p< 0.001) and orthopedic ( 2: 13% versus 7%, p=0.053) problems. Five years after surgery, quality-of-life and patient satisfaction were much lower after rTHA than after pTHA (HHS < 70; 31% versus 9%, p< 0.001; satisfaction score 8: 68% versus 85%, p< 0.001). Adjustment for the preoprative status (ASA, medical and orthopedic comorbidity, BMI, gender, age) attenuated these differences which nevertheless remained significant [non-adjusted HHS difference: 11.5 (95%CI: 7.4–15.7); adjusted difference: 8.8 (95%CI: 5.5–12.1)]. In both groups, a low HHS was associated with BMI ≥ 30, poor preoperative function, 2 joints affected, elderly age. Obesity was associated with even poorer results after rTHA than after pTHA (non-adjusted difference, p=0.026).

Discussion: Quality-of-life and patient satisfaction at five years were clearly poorer after rTHA than after pTHA. This is in agreement with data in the literature. The difference is explained in particular by greater patient age and more associated comorbidities for rTHA. Obesity is a prognostic factor which is more unfavorable after rTHA than after pTHA.

Conclusion: Considering the risks and benefits of revision surgery, it is important to recognize not only the surgical factors but also the characteristic features of the patients.