SA Orthopaedic Journal
On-line version ISSN 2309-8309
RYAN, P et al. Technical difficulty in component sizing and positioning in humeral resurfacing: Relationship to clinical outcomes. SA orthop. j. [online]. 2015, vol.14, n.3, pp. 32-42. ISSN 2309-8309. http://dx.doi.org/10.17159/2309-8309/2015/V14N3A3.
INTRODUCTION: Resurfacing of the glenohumeral joint has gained popularity since its first introduction. Among other advantages, it is reported to allow closer replication of individual anatomy - failure of which may produce inferior clinical results. We review a cohort of patients who had undergone proximal humeral resurfacing, to evaluate certain radiological parameters of component sizing and positioning, and to correlate these with the clinical outcomes. MATERIALS AND METHODS: From January 2000 to March 2011, 51 humeral resurfacing procedures were performed in 49 patients. Patients were contacted for review, and assessed using patient-reported outcome measures. An Oxford Shoulder Score (OSS) as well as a subjective satisfaction and outcome questionnaire were completed, as well as details regarding further surgery or revision. Radiographs were evaluated for component size, offset, inclination and height. Two patients had demised, ten patients were not contactable, and in four the medical files had been lost. In the remaining 35 shoulders, the average follow-up was 5.43 years. The mean age at time of surgery was 64.8 years (range 36 to 84). RESULTS: Complications included eight revisions (average 2.4 years post-surgery), while a further one patient awaits revision. The mean OSS in the unrevised shoulders was 36.1 (range 10 to 48). There was no difference between the revised and unrevised group for peri-operative variables (pre-op diagnosis, smoking status, age, gender, surgeon involved), or any of the radiographic variables (inclination, offset, prosthesis height, increase in head size). In the unrevised group, there was no correlation between the OSS and radiographic measurements of offset, inclination or head height. Prostheses that subjectively appeared mal-sized or mal-positioned obtained better OSSs and subjective satisfaction scores. Revised cases were all subjectively satisfied post revision to stemmed total shoulder replacement. CONCLUSION: We have demonstrated difficulties in correct sizing and component placement as evident by the post-operative radiographic analysis, but are unable to correlate these with clinical scores. We have encountered a wide range of patient-reported shoulder scores and levels of satisfaction which, however unexplainably, have shown better scores for subjectively mal-sized and mal-positioned prostheses.
Keywords : humeral resurfacing; shoulder replacement; shoulder arthroplasty.