Thus, I read with great interest the recent paper entitled “Prosthetic resurfacing of engaging posterior capitellar defects in recurrent posterolateral rotatory (PLRI) of the elbow,” by Rotman et al. [10]. The authors reported five patients with PLRI and associated Osborne-Cotterill lesions that were surgically treated with repair/reconstruction of the lateral collateral ligament and reconstruction of the capitellar defect with a metal prosthesis. The implant was originally designed for metatarsal head resurfacing (HemiCAP Toe Classic, Arthrosurface), and so this was an off-label use in the elbow joint, as acknowledged by the authors. Mid-term follow-up (median, 4.5 years postoperatively; range, 1–6 years) showed excellent results with no instability, prothesis loosening or reoperation, except for mild arthritis in one patient. This study has several strengths. Given that LUCL reconstruction without addressing the bony lesion can cause recurrent instability [2], resurfacing of the engaging posterior capitellar defect shown in this study can be a useful option as a concomitant procedure in LUCL reconstruction. This study also reminds the treating surgeons of the importance of Osborne-Cotterill lesions in elbow instability. Off-label use of a metatarsal prosthesis is a limitation of this study, which may not be allowed elsewhere. Metatarsal resurfacing prostheses also may not be available or familiar to all elbow surgeons.

Future studies related to Osborne-Cotterill lesions are needed. First, a well-organized randomized clinical trial comparing ligament reconstruction with or without addressing bony lesions should be conducted to establish the indications for the combined bony procedure. Given the relative rarity of this lesion, a multicenter collaboration will be necessary. We should also address the issue of how the size of bony defects may impact treatment. As Osborne and Cotterill [1] first correlated capitellar or radial head lesions to bone loss in the humeral head (Hill-Sachs lesion) or anterior aspect of the glenoid with recurrent shoulder instability, we should measure the amount of capitellar bone loss with three-dimensional computed tomography scans, like glenoid bone loss measurement is conducted in the shoulder. Based on this measurement, we can obtain clearer indications for when to use a ligament procedure alone or a combined bony procedure in individual patients. Such studies results will help surgeons establish the optimal treatment strategy for Osborne-Cotterill lesions, with the current study acting as the precursor of advancements in treatment.