We report an unusual case of a tenosynovial giant cell tumor (TGCT) in a patient who received a total knee arthroplasty (TKA) for medial knee osteoarthritis with synovial osteochondromatosis (SO). A 72‐year‐old woman underwent conventional jig‐based simultaneous bilateral bicruciate‐stabilized TKA. Four years after the surgery, she came to our hospital with a chief complaint of persistent pain in the right knee only, with recurrent spontaneous hemarthrosis. We performed a synovectomy with open excisional debridement and a polyethylene exchange. Histologic analysis of synovial samples was consistent with TGCT. We present the imaging and pathological details of the first case of de novo TGCT that occurred in the background of SO after TKA.

Compartment syndrome of the forearm is a well-described clinical entity, but only a few case reports on hand compartment syndromes have been reported due to its rarity. The early recognition and treatment of this potential threat to the limb are important in order to prevent permanent disability and other life-threatening complications. This is a documented case report on the late presentation of compartment syndrome of the hand following a fall.

This case report from a Level 1 trauma center describes a novel surgical technique to remove a cannulated intramedullary nail, broken at the distal aspect, from the femur. We present a 40-year-old male who sustained a hardware failure, breaking his medullary nail at the distal aspect 7 weeks postoperatively while performing water aerobics. The broken implant was successfully extracted without complication, and a subsequent nail was exchanged. A benefit of this technique is avoiding a femoral osteotomy, which may prove useful for the unique and difficult case of distally broken nails.

Introduction: Total hip arthroplasty (THA) is a commonly performed and highly successful surgical procedure. Metal-on-metal (MoM) THA implants were introduced two decades ago and subsequently recalled due to high early revision rates. Acetabular cup erosion and fragmentation secondary to chronic edge loading causing delayed instability are rare but devastating complications of MoM THA warranting expeditious revision surgery. Case Presentation: We report a 70-year-old male with a history of bilateral MoM THA who presented with left hip instability. In addition to the radiographic and clinical features of hip instability, macroscopic examination at revision surgery revealed extensive erosion and fragmentation of the antero-superior margin of the implanted cup, osteolysis, and widespread metallosis of the periarticular soft tissues. Discussion: This case highlights a significant adverse complication of MoM THA. Despite the industry's wide discontinuation and recall of these implants, MoM hip arthroplasty implants are present in many patients, who are all at risk of developing similar complications. Guidelines for the surveillance and treatment of both symptomatic and asymptomatic MoM THAs have been reported, although ambiguity remains in the optimal approach for managing patients with existing MoM THA. Conclusion: Failure of MoM hip arthroplasty is most commonly the result of adverse reaction to metal debris. We present a novel mechanism of failure in a patient presenting with late instability due to asymmetric wear of the MoM bearing surface.. While it is uncertain whether early intervention in this patient may have prevented this complication, arthroplasty surgeons should be aware of the various modes of failure for MoM hip implants, as expeditious revision surgery is often required.

Adequate bone curettage is crucial for treating epiphyseal chondroblastomas. However, achieving adequate curettage while minimizing damage to the articular cartilage is challenging. For lesions at the center of the distal femoral epiphysis, curettage using an intercondylar approach may have better oncological and functional outcomes than the conventional extra-articular approach from the wall of the epiphysis. We herein present a case of a 22-year-old male patient with a chondroblastoma of the femoral medial condyle close to the intercondylar fossa. Intercondylar curettage was performed at the site of the insertion of the posterior cruciate ligament (PCL). Maximal knee flexion allowed for good exposure of the lesion, and a direct approach to the tumor led to adequate curettage. Careful suturing of the PCL and postoperative care resulted in sufficient joint stability. The patient showed no signs of local recurrence or osteoarthritic changes at his 16-month follow-up. The intercondylar approach could be a surgical technique worth considering for the treatment of chondroblastoma in the distal femoral epiphysis, particularly for lesions located near the intercondylar fossa.

A 43-year-old man presented with chronic left hip pain that had increased in severity in the last week. Imaging studies discovered a mass in the iliopsoas muscle. The mass was excised, and pathological examination revealed pleomorphic rhabdomyosarcoma. The patient was followed up for 2 years and demonstrated no recurrence, with good clinical results. Clinicians should follow a systematic diagnostic approach involving a detailed medical history, a comprehensive physical examination, imaging studies, and laboratory tests to evaluate masses in the iliopsoas region, leading to timely diagnosis and appropriate management. Rhabdomyosarcoma is already a rare malignancy in adults. Therefore, having it in the iliopsoas compartment makes this case unique. To our knowledge, there was only one previously reported case of rhabdomyosarcoma involving the iliopsoas.

Herein, we present a rare case of periprosthetic joint infection (PJI) which was triggered by an infection with a latent subcutaneous cyst on the thigh and occurred in a strange course following total knee arthroplasty (TKA). An 87-year-old female underwent right TKA followed by left TKA 5 months later. Six weeks after left TKA, a painful subcutaneous induration appeared in the left medial thigh. Magnetic resonance imaging revealed a 30∗50-mm multifocal mass. The cystic fluid was brown and cloudy, indicating an infected cyst. Oral antimicrobial therapy was initiated for 7 days. Nine weeks after the left TKA, a left calcaneal fracture occurred. Subsequently, edema of the lower extremities and pain in the left knee gradually developed. Arthrocentesis was performed twice: joint fluid Gram staining and culture examination were negative. However, at 12.5 weeks, an alpha-defensin test of the synovial fluid was positive. Therefore, PJI was diagnosed. DAIR was performed, followed by multiantibiotic therapy. The infection subsided gradually. Edema of the lower limbs was treated with oral diuretics, lymphatic massage, and compression stockings. Consequently, the lower limb edema also improved. In this case, infection of a latent subcutaneous cyst in the thigh occurred and spread around the prosthesis due to leg edema, which was associated with loss of lower limb motion due to a calcaneal fracture. The presence of a potential thigh subcutaneous cyst is a risk factor for PJI. Moreover, lower extremity edema occurs by decreasing lower extremity motion, such as after a calcaneal fracture, and it increases the risk of extending extra-articular infection to the PJI. Potential thigh subcutaneous cysts and lower extremity edema are risk factors for the development of PJI. Orthopedic surgeons need to be aware of these facts during follow-up after TKA.

A healthy 16-year-old girl presented with an osteochondral fracture of the posterior aspect of the lateral femoral condyle (LFC) following patellar dislocation. Satisfactory results were obtained with osteochondral fragment fixation and medial patellofemoral ligament (MPFL) reconstruction. To the best of our knowledge, this is only the third reported case of an osteochondral fracture of the posterior LFC. However, we believe that the mechanism of injury differed from that in the two previous cases.

Fibrodysplasia ossificans progressiva is an ultrarare disorder of endochondral ossification. It is unfamiliar to most care providers in low-income countries such as Ethiopia. Even though the clinical presentation is typical, most cases remain misdiagnosed in our region. Moreover, we hypothesize that many such cases undergo unnecessary or harmful interventions for a painless lump. In Ethiopia, with a population of approximately 120 million, only one case has been reported in the literature so far. We present two cases that were referred to our institution for a biopsy of a mass. This report is aimed at summarizing the typical presentation of the disease and at highlighting the harmful interventions one should avoid in such patients. We also hope that this report serves as an entry point to try to find more patients with this similar condition early in their clinical course. Furthermore, we believe that in order to lessen the overall impact of the illness, it is crucial to provide caregivers with health education about the causes of disease flare-ups.