A.A. Malone

Assessment of osteoarthritis after reconstruction of the anterior cruciate ligament: A STUDY USING SINGLE-PHOTON EMISSION COMPUTED TOMOGRAPHY AT TEN YEARS

We used single-photon emission computed tomography (SPECT) to determine the long-term risk of degenerative change after reconstruction of the anterior cruciate ligament (ACL). Our study population was a prospective series of 31 patients with a mean age at injury of 27.8 years (18 to 47) and a mean follow-up of ten years (9 to 13) after bone-patellar tendon-bone reconstruction of the ACL. The contralateral normal knee was used as a control. All knees were clinically stable with high clinical scores (mean Lysholm score, 93; mean Tegner activity score, 6). Fifteen patients had undergone a partial meniscectomy and ACL reconstruction at or before reconstruction of their ACL. In the group with an intact meniscus, clinical symptoms of osteoarthritis (OA) were found in only one patient (7%), who was also the only patient with marked isotope uptake on the SPECT scan compatible with OA. In the group which underwent a partial meniscectomy, clinical symptoms of OA were found in two patients (13%), who were among five (31%) with isotope uptake compatible with OA. Only one patient (7%) in this group had evidence of advanced OA on plain radiographs. The risk of developing OA after ACL reconstruction in this series is very low and lower than published figures for untreated ACL-deficient knees. There is a significant increase (p < 0.05) in degenerative change in patients who had a reconstruction of their ACL and a partial meniscectomy compared with those who had a reconstruction of their ACL alone.

Total Elbow Arthroplasty in Obese Patients

BACKGROUND The prevalence of obesity in the United States has increased in recent decades. The aim of this study was to evaluate the influence of obesity in patients undergoing primary total elbow arthroplasty. METHODS From 1987 to 2006, 723 primary semiconstrained, linked total elbow arthroplasties were performed in 654 patients. The average patient age (and standard deviation) at the time of surgery was 62.3 ± 13.7 years, with 550 total elbow arthroplasties (76%) performed in women. Total elbow arthroplasties were used to treat inflammatory conditions in patients undergoing 378 total elbow arthroplasties (52%) and to treat acute traumatic or posttraumatic conditions in patients undergoing 310 total elbow arthroplasties (43%). Patients were classified as non-obese (having a body mass index of <30 kg/m2) in 564 total elbow arthroplasties (78%) and as obese (having a body mass index of ≥30 kg/m2) in 159 total elbow arthroplasties (22%). The median duration of follow-up was 5.8 years (range, zero to twenty-five years). Survivorship of total elbow arthroplasty was estimated with use of the Kaplan-Meier method. The effect of obesity on risk of total elbow arthroplasty revision was estimated with use of Cox regression models, adjusting for age, sex, body mass index, and indication. RESULTS A total of 118 revisions (16%) were performed. The ten-year survival rate for total elbow arthroplasty revision for any reason was 86% (95% confidence interval, 82% to 89%) in non-obese patients compared with 70% (95% confidence interval, 60% to 79%) in obese patients (p < 0.05). The ten-year survival rate for total elbow arthroplasty revision for mechanical failure was 88% (95% confidence interval, 84% to 91%) in non-obese patients compared with 72% (95% confidence interval, 61% to 81%) in obese patients (p < 0.05). Severely obese patients (those with a body mass index of 35 to <40 kg/m2) had a significantly higher risk of total elbow arthroplasty revision for any reason (hazard ratio, 3.08 [95% confidence interval, 1.61 to 5.45]; p < 0.05) and mechanical failure (hazard ratio, 3.10 [95% confidence interval, 1.47 to 5.89]; p < 0.05) compared with non-obese patients. CONCLUSIONS Obesity adversely influences the performance of elbow replacement after primary total elbow arthroplasty. Obese patients being considered for elbow replacement surgery should be counseled accordingly.

Validation of the Stanmore percentage of normal shoulder assessment.

Background and Purpose: The Stanmore Percentage of Normal Shoulder Assessment (SPONSA) is a patient-reported outcome measure (PROM). The score assesses pain, range of movement, strength, stability and function of the shoulder. The aim of this work was to formally validate the SPONSA. Materials and Methods: Validation of this score was carried out by measuring reproducibility, construct validity and sensitivity to change. Time to completion was also recorded. The Oxford Shoulder Score (OSS) and Constant Score (CS) were used for comparison. These assessments were performed with 61 individuals undergoing shoulder interventions. Results: There was excellent preoperative reproducibility in both intra- and inter-observer groups. The SPONSA had a 0.79 correlation with the OSS and 0.78 with the CS. The overall effect size of the SPONSA was 0.72, which was comparable to OSS (0.65) and greater than CS (0.34), implying equal or better sensitivity to change. Conclusions: The SPONSA is practical and quick to perform and also a reproducible and a sensitive instrument. This simple PROM is a commendable addition to the existing validated scoring methods for the shoulder. Level of Evidence: I; testing of previously developed diagnostic criteria on consecutive patients (with universally applied reference “gold” standard).

Sciatic neurostenalgia: caused by total hip arthroplasty, cured by late neurolysis

We describe a patient with a painful sciatic neuropathy after total hip arthroplasty. Treatment was confined to neuroleptic and analgesic agents until neurolysis at seven years abolished pain and restored function.

Muscle activation patterns in patients with recurrent shoulder instability

Purpose: The aim of this study is to present muscle patterns observed with the direction of instability in a series of patients presenting with recurrent shoulder instability. Materials and Methods: A retrospective review was carried out on shoulder instability cases referred for fine wire dynamic electromyography (DEMG) studies at a specialist upper limb centre between 1981 and 2003. An experienced consultant clinical neurophysiologist performed dual needle insertion into four muscles (pectoralis major (PM), latissimus dorsi (LD), anterior deltoid (AD) and infraspinatus (IS)) in shoulders that were suspected to have increased or suppressed activation of muscles that could be contributing to the instability. Raw EMG signals were obtained while subjects performed simple uniplanar movements of the shoulder. The presence or absence of muscle activation was noted and compared to clinical diagnosis and direction of instability. Results: A total of 140 (26.6%) shoulders were referred for fine wire EMG, and 131 studies were completed. Of the shoulders tested, 122 shoulders (93%) were identified as having abnormal patterns and nine had normal patterns. PM was found to be more active in 60% of shoulders presenting with anterior instability. LD was found to be more active in 81% of shoulders with anterior instability and 80% with posterior instability. AD was found to be more active in 22% of shoulders with anterior instability and 18% with posterior instability. IS was found to be inappropriately inactive in only 3% of shoulders with anterior instability but in 25% with posterior instability. Clinical assessment identified 93% of cases suspected to have muscle patterning, but the specificity of the clinical assessment was only correct in 11% of cases. Conclusion: The DEMG results suggest that increased activation of LD may play a role in both anterior and posterior shoulder instability; increased activation of PM may play a role in anterior instability.

Entrapment of a displaced common peroneal nerve following knee ligament reconstruction

We present a case of disruption of the posterolateral corner of the knee with avulsion of the tendon of biceps femoris. Repair and reconstruction included an allogenic tendon graft to replace the posterior cruciate ligament. Surgery was followed by a complete common peroneal nerve palsy. Revision surgery revealed that the nerve had been displaced anteriorly by avulsion of the biceps tendon and the tendon graft encircled it. Release of the nerve restored normal function at five months.

Revision of total elbow replacement by exchange cementing

We report the effectiveness of revision of total elbow replacement by re-cementing. Between 1982 and 2004, 53 elbows in 52 patients were treated with re-cementing of a total elbow replacement into part or all of the existing cement mantle or into the debrided host-bone interface, without the use of structural bone augmentation or a custom prosthesis. The original implant revision was still in situ and functional in 42 of 53 elbows (79%) at a mean of 94.5 months (26 to 266) after surgery. In 31 of these 42 elbows (74%) the Mayo Elbow Performance Score was good or excellent. Overall, of the 53 elbows, 18 (34%) required re-operation, ten (19%) for loosening. A classification system was developed to identify those not suitable for revision by this technique, and using this we have showed that successful re-implantation is statistically correlated to properly addressing the bone deficiency for both the humeral (p = 0.005) and the ulnar (p = 0.039) components.

Five-year follow-up of a prospective randomised trial comparing ceramic-on-metal and metal-on-metal bearing surfaces in total hip arthroplasty

Aims The primary aim of this independent prospective randomised trial was to compare serum metal ion levels for ceramic‐on‐metal (CoM) and metal‐on‐metal (MoM) bearing surfaces in total hip arthroplasty (THA). Our one‐year results demonstrated elevation in metal ion levels above baseline with no significant difference between the CoM and MoM groups. This paper reviews the five‐year data. Patients and Methods The implants used in each patient differed only in respect to the type of femoral head (ceramic or metal). At five‐year follow‐up of the 83 enrolled patients, data from 67 (36 CoM, 31 MoM) was available for comparison. Results The mean serum cobalt (Co) and chromium (Cr) ion levels remained above baseline in both groups (CoM: Co 1.16 &mgr;g/l (0.41 to 14.67), Cr 1.05 &mgr;g/l (0.16 to 12.58); MoM: Co 2.93 &mgr;g/l (0.35 to 30.29), Cr 1.85 &mgr;g/l (0.36 to 17.00)) but the increase was significantly less in the CoM cohort (Co difference p = 0.001, Cr difference p = 0.002). These medium‐term results, coupled with lower revision rates from national joint registries, suggest that the performance of CoM THA may be superior to that of MoM. Conclusion While both bearing combinations have since been withdrawn these results provide useful information for planning clinical surveillance of CoM THAs and warrants continued monitoring.

Type IV acromioclavicular joint dislocation associated with a mid-shaft clavicle malunion

This reports presents the case of a combined clavicle fracture malunion and chronic Type IV acromioclavicular (AC) joint dislocation. The patient was seen acutely in the emergency department following a mountain bike accident at which time the clavicle fracture was identified and managed conservatively however the AC dislocation was not diagnosed. The patient presented 25 months following the injury with persistent pain and disability and was treated with clavicle osteotomy and AC stabilization. We document the clinical details, surgical treatment and outcome.