Anterior knee pain from the evolutionary perspective.

BACKGROUND: This paper describes the evolutionary changes in morphology and orientation of the PFJ using species present through our ancestry over 340 million years. METHODS: 37 specimens from the Devonian period to modern day were scanned using a 64-slice CT scanner. 3D geometries were created following routine segmentation and anatomical measurements taken from standardised bony landmarks. RESULTS: Findings are described according to gait strategy and age. The adoption of an upright bi-pedal stance caused a dramatic change in the loading of the PFJ which has subsequently led to changes in the arrangement of the PFJ. From Devonian to Miocene periods, our sprawling and climbing ancestors possessed a broad knee with a shallow, centrally located trochlea. A more rounded knee was present from the Paleolithic period onwards in erect and bipedal gait types (aspect ratio 0.93 vs 1.2 in late Devonian), with the PFJ being placed lateral to the midline compared to the medial position in quadrapeds. The depth of the trochlea groove was maximal in the Miocene period of the African ground apes with associated acute sulcus angles in Gorilla (117°) becoming more flattened towards the modern human (138°). CONCLUSIONS: The evolving bipedal gait lead to anteriorisation of the patellofemoral joint, flattening of the trochlea sulcus, in a more lateral, dislocation prone arrangement. Ancestral developments might help explain the variety of presentations of anterior knee pain and patellofemoral instability.

Management of tenosynovial giant cell tumour of the foot and ankle.

AIMS: Tenosynovial giant cell tumour (TGCT) is one of the most common soft-tissue tumours of the foot and ankle and can behave in a locally aggressive manner. Tumour control can be difficult, despite the various methods of treatment available. Since treatment guidelines are lacking, the aim of this study was to review the multidisciplinary management by presenting the largest series of TGCT of the foot and ankle to date from two specialized sarcoma centres. METHODS: The Oxford Tumour Registry and the Leiden University Medical Centre Sarcoma Registry were retrospectively reviewed for patients with histologically proven foot and ankle TGCT diagnosed between January 2002 and August 2019. RESULTS: A total of 84 patients were included. There were 39 men and 45 women with a mean age at primary treatment of 38.3 years (9 to 72). The median follow-up was 46.5 months (interquartile range (IQR) 21.3 to 82.3). Localized-type TGCT (n = 15) predominantly affected forefoot, whereas diffuse-type TGCT (Dt-TGCT) (n = 9) tended to panarticular involvement. TGCT was not included in the radiological differential diagnosis in 20% (n = 15/75). Most patients had open rather than arthroscopic surgery (76 vs 17). The highest recurrence rates were seen with Dt-TGCT (61%; n = 23/38), panarticular involvement (83%; n = 5/8), and after arthroscopy (47%; n = 8/17). Three (4%) fusions were carried out for osteochondral destruction by Dt-TGCT. There were 14 (16%) patients with Dt-TGCT who underwent systemic treatment, mostly in refractory cases (79%; n = 11). TGCT initially decreased or stabilized in 12 patients (86%), but progressed in five (36%) during follow-up; all five underwent subsequent surgery. Side effects were reported in 12 patients (86%). CONCLUSION: We recommend open surgical excision as the primary treatment for TGCT of the foot and ankle, particularly in patients with Dt-TGCT with extra-articular involvement. Severe osteochondral destruction may justify salvage procedures, although these are not often undertaken. Systemic treatment is indicated for unresectable or refractory cases. However, side effects are commonly experienced, and relapses may occur once treatment has ceased. Cite this article: Bone Joint J 2021;103-B(4):788-794.

Giant cell tumor with pathologic fracture: should we curette or resect?

BACKGROUND: Approximately one in five patients with giant cell tumor of bone presents with a pathologic fracture. However, recurrence rates after resection or curettage differ substantially in the literature and it is unclear when curettage is reasonable after fracture. QUESTIONS/PURPOSES: We therefore determined: (1) local recurrence rates after curettage with adjuvants or en bloc resection; (2) complication rates after both surgical techniques and whether fracture healing occurred after curettage with adjuvants; and (3) function after both treatment modalities for giant cell tumor of bone with a pathologic fracture. METHODS: We retrospectively reviewed 48 patients with fracture from among 422 patients treated between 1981 and 2009. The primary treatment was resection in 25 and curettage with adjuvants in 23 patients. Minimum followup was 27 months (mean, 101 months; range, 27-293 months). RESULTS: Recurrence rate was higher after curettage with adjuvants when compared with resection (30% versus 0%). Recurrence risk appears higher with soft tissue extension. The complication rate was lower after curettage with adjuvants when compared with resection (4% versus 16%) and included aseptic loosening of prosthesis, allograft failure, and pseudoarthrosis. Tumor and fracture characteristics did not increase complication risk. Fracture healing occurred in 24 of 25 patients. Mean Musculoskeletal Tumor Society score was higher after curettage with adjuvants (mean, 28; range, 23-30; n = 18) when compared with resection (mean, 25; range, 13-30; n = 25). CONCLUSIONS: Our observations suggest curettage with adjuvants is a reasonable option for giant cell tumor of bone with pathologic fractures. Resection should be considered with soft tissue extension, fracture through a local recurrence, or when structural integrity cannot be regained after reconstruction. LEVEL OF EVIDENCE: Level III, therapeutic study. See Guidelines for Authors for a complete description of levels of evidence.

A multidisciplinary approach to giant cell tumors of tendon sheath and synovium--a critical appraisal of literature and treatment proposal.

Giant cell tumors deriving from synovium are classified into a localized (GCT of tendon sheath; GCT-TS) and diffuse form (diffuse-type GCT, Dt-GCT). We propose a multidisciplinary management based upon a systematic review and authors' opinion. Open excision for GCT-TS and open synovectomy (plus excision) for Dt-GCT is advised to reduce the relatively high recurrence risk. External beam radiotherapy should be considered in severe cases, as Dt-GCT commonly extends extra-articular.

Hip resurfacing and pseudotumour.

Metal on metal hip resurfacing has been used widely over the last ten years but there has been recent concern about destructive soft tissue reactions, which have been called pseudotumours by some authors. This has generated considerable controversy. This review explains why pseudotumours occur after resurfacing and how they can be prevented. It also supports the continued use of resurfacing in appropriate patients by appropriately trained surgeons.

Osteoclast formation and function in pigmented villonodular synovitis.

Pigmented villonodular synovitis (PVNS) is a synovial tumour-like lesion that frequently causes osteolysis. PVNS contains numerous macrophages and osteoclast-like giant cells. In this study, we have analysed the cytochemical and functional characteristics of mononuclear and multinucleated cells in PVNS and determined the cellular and humoral mechanisms underlying giant cell formation and resorption in PVNS. Giant cells and CD14(+) and CD14(-) mononuclear cell populations were isolated from PVNS synovial tissue and cultured alone or in the presence and absence of the osteoclastogenic factors, RANKL and M-CSF. Osteoclast formation and activity was assessed by expression of TRAP and evidence of lacunar resorption. Giant cells in PVNS expressed an osteoclast-phenotype (CD51(+) , TRAP(+) , CD14(-) , HLA-DR(-) ) and were formed only in cultures of mononuclear cells that expressed the macrophage marker CD14. Osteoclast formation required RANKL and occurred in both the presence and absence of exogenous M-CSF. CD14(-) cells in PVNS expressed RANKL. Lacunar resorption by PVNS-derived giant cells was abolished by the addition of the bisphosphonate, zoledronate. Our findings indicate that osteoclasts form by a RANKL-dependent mechanism from CD14(+) mononuclear phagocytes in PVNS. Osteoclast formation occurred even in the absence of exogenous M-CSF, a finding which is in keeping with over-expression of M-CSF playing a pathogenic role in this condition. Anti-osteoclast resorptive treatment may be useful to control osteolysis in PVNS.

Medial tibial plateau fracture and the Oxford unicompartmental knee.

Tibial plateau fracture is a rare complication of unicompartmental knee arthroplasty. The fracture almost always occurs during surgery, and it is likely to be the result of a technical error, usually an unnecessarily deep vertical saw cut into the proximal tibia. However, anything that weakens or overloads the proximal tibia may contribute to fracture, such as damage to the posterior cortex, excess removal of bone particularly in small patients with osteopenic bones, inadequate preparation of the keel slot, or use of excessive force with a heavy hammer. This series of eight case reports presents our experience with this complication after medial Oxford unicompartmental knee arthroplasty and outlines a treatment protocol.