Background: The modified Lapidus is a surgical procedure for managing moderate to severe hallux valgus, especially in the presence of first tarsometatarsal joint arthritis or hypermobility. It has good long-term results but reportedly can lead to transfer metatarsalgia due to inherent shortening of the first metatarsal. Methods: A retrospective analysis of all adult patients who underwent a modified Lapidus procedure during a 3-year period was performed. Clinical notes were evaluated to look for nonunion or any other complications related to the surgery. Pre- and postoperative standard weightbearing radiographs were used to establish the relative metatarsal length (RML), intermetatarsal angle (IMA), hallux valgus angle (HVA), and distal metatarsal articular angle (DMMA). A total of 69 modified Lapidus procedures were identified, with 32 included in the study. Results: The mean pre- and postoperative RMLs were −0.8 and −4.9 mm, respectively. The average RML shortening due to the procedure was −4.1 ( P < .0001). The mean pre- and postoperative IMAs were 15 and 5 degrees, respectively ( P < .0001). The mean pre- and postoperative HVAs were 33 and 9 degrees, respectively ( P < .0001). One patient reported transfer metatarsalgia, which was attributed to elevation of the first metatarsal. Conclusion: We found a statistically significant degree of shortening of the relative length of the first metatarsal without any clinically significant metatarsalgia. The low rate of transfer metatarsalgia following the modified Lapidus procedure could be attributed to the sagittal plane correction and stability obtained by performing a first tarsometatarsal fusion. Level of Evidence: Level IV, retrospective case series.

INTRODUCTION: Reports of fatigue failure of the femoral component of a total knee arthroplasty (TKA) is scanty in the literature. As a result, there are no clearly defined risk factors to aid us in predicting fatigue failure of an implant. Furthermore, these patients may present with non-specific knee pain, which may or may not be well tolerated, depending on the stability of the implant. We report a case of fatigue failure of a poorly cemented femoral component of a TKA in a 72-year-old female, approximately seven years after the initial surgery CASE REPORT: A 72-year-old female presented to our tertiary level arthroplasty unit with new-onset knee pain approximately seven years after undergoing a TKA at our unit. She reported hearing a crack six months earlier, while standing up from a seated position. She had initially presented to her local clinic, but the pathology was missed. She received revision surgery at our institution and was doing well at early follow-up. DISCUSSION: We reviewed the literature on fatigue failure of femoral components in TKA in an attempt to define risk factors. We also summarised all cases of femoral component fatigue failure in the English literature. CONCLUSION: Although femoral component fatigue failure in TKA is rare, the majority of cases have attributed the failure to poor surgical technique. Despite this, certain implants have been failing more often than others, and proposed mechanisms for this exist. Orthopaedic surgeons need to be aware of which implant designs are prone to failure, as well as how meticulous surgical technique can reduce the chances of fatigue failure. Level of evidence: Level 5 Keywords: femoral component, total knee arthroplasty, fatigue failure, stress fracture

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