Moran, Steven L.

Vascularized toe joint transfer for finger proximal interphalangeal joint reconstruction can result in sub-optimal arc of motion and extension lag due to inappropriate intercalated bony segment length. We investigated the impact of intercalated segment length on passive arc of motion and extension lag of the reconstructed proximal interphalangeal joint. Cadaveric intercalated joint grafts were harvested from lesser toes and transferred to cadaveric fingers. The pre-determined finger proximal interphalangeal joint defect size was 2 cm. Three different intercalated segment lengths were inserted and resulting proximal interphalangeal joint arc of motion and extension lag were measured. The average arc of motion of finger proximal interphalangeal joints was 81° and 54° for toe proximal interphalangeal joints. Long intercalated segments had an average arc of motion of 30° with 32° extension lag. Equal-length intercalated segments had an average 49° arc of motion with 15° extension lag. Short intercalated segments had an average arc of motion of 71° with 8° extension lag. Shorter intercalated segments provide the greatest reduction in extension lag.

Objectives The present study describes a novel technique for revitalising allogenic intrasynovial tendons by combining cell-based therapy and mechanical stimulation in an ex vivo canine model. Methods Specifically, canine flexor digitorum profundus tendons were used for this study and were divided into the following groups: (1) untreated, unprocessed normal tendon; (2) decellularised tendon; (3) bone marrow stromal cell (BMSC)-seeded tendon; and (4) BMSC-seeded and cyclically stretched tendon. Lateral slits were introduced on the tendon to facilitate cell seeding. Tendons from all four study groups were distracted by a servohydraulic testing machine. Tensile force and displacement data were continuously recorded at a sample rate of 20 Hz until 200 Newton of force was reached. Before testing, the cross-sectional dimensions of each tendon were measured with a digital caliper. Young’s modulus was calculated from the slope of the linear region of the stress-strain curve. The BMSCs were labeled for histological and cell viability evaluation on the decellularized tendon scaffold under a confocal microscope. Gene expression levels of selected extracellular matrix tendon growth factor genes were measured. Results were reported as mean ± SD and data was analyzed with one-way ANOVAs followed by Tukey’s post hoc multiple-comparison test. Results We observed no significant difference in cross-sectional area or in Young’s modulus among the four study groups. In addition, histological sections showed that the BMSCs were aligned well and viable on the tendon slices after two-week culture in groups three and four. Expression levels of several extracellular matrix tendon growth factors, including collagen type I, collagen type III, and matrix metalloproteinase were significantly higher in group four than in group three (p < 0.05). Conclusion Lateral slits introduced into de-cellularised tendon is a promising method of delivery of BMSCs without compromising cell viability and tendon mechanical properties. In addition, mechanical stimulation of a cell-seeded tendon can promote cell proliferation and enhance expression of collagen types I and III in vitro. Cite this article: J. H. Wu, A. R. Thoreson, A. Gingery, K. N. An, S. L. Moran, P. C. Amadio, C. Zhao. The revitalisation of flexor tendon allografts with bone marrow stromal cells and mechanical stimulation: An ex vivo model revitalising flexor tendon allografts. Bone Joint Res 2017;6:179–185. DOI: 10.1302/2046-3758.63.BJR-2016-0207.R1.

Background: Giant cell tumor (GCT) of bone is a benign, though locally aggressive tumor, classically described as an eccentric lytic lesion, often with cortical expansion and destruction. It typically involves the metaphysis or epiphysis of long bones in skeletally mature patients, with a slight female predominance. The incidence in the small bones of the hand has been reported to be 2% to 5%. Methods: Treatment options have evolved in recent years, and currently include intralesional curettage with or without adjuvant therapy, wide resection, and occasionally amputation. Results: In this report, we present a long-term follow-up (10 years) of a patient with GCT involving a metacarpal, who was initially reconstructed with a metacarpal head allograft, which was eventually revised to a metacarpophalangeal (MCP) total joint arthroplasty. Conclusions: To our knowledge, this is the only report of pyrocarbon being used for tumor reconstruction and the only report of late MCP allograft salvage.

Objective: Vascularized toe joint transfer for finger proximal interphalangeal joint (PIPJ) reconstruction is a well-described technique in the literature. However, the reconstructed PIPJ is known to have issues with suboptimal range of motion and extension lag. One of the reasons for this problem is the length of the intercalated bony segment. There is a lack of evidence and consensus regarding the optimal length of the intercalated segment. This study hence was performed to determine the impact of the intercalated segment length on the subsequent passive arc of motion (AOM) and extension lag of the reconstructed PIPJ. Materials and Methods: We harvested the intercalated joint graft (the toe PIPJ along with its associated extensor tendons) from the lesser toes and transferred it to the finger of cadavers. A predetermined constant PIPJ defect size of 2 cm was created on the finger. By insetting 3 different lengths of the intercalated segment to the finger PIPJ, we investigated the effect of shortened (1.5 cm), exact (2.0 cm), or lengthened (2.5 cm) intercalated segment lengths on the AOM and extension lag of the reconstructed PIPJ. Results: The average AOM of finger PIPJ was 81.0° ± 19.1° and that of the toe PIPJ was 53.6° ± 16.1°. In the group with longer intercalated segment, the average AOM was 29.9° ± 10.5° with an extension lag of 32° ± 11.7°. In the group with equal intercalated segment length, the average AOM was 49.1° ± 11.5° with an extension lag of 15.4° ± 10.6°. In the group with shorter intercalated segment, the average AOM was 70.9° ± 12.6° with an extension lag of 8.4° ± 8.9°. Conclusions: From our study, shortening the intercalated segment may provide the most reduction in the extension lag of the reconstructed PIPJ. Future studies could involve further refinement of the amount of length to be shortened. This would probably lie between 0 to 5 mm.

Background: Multiple enchodromatosis of bone, termed Ollier’s disease, or Maffucci syndrome when associated with hemangiomas, is a rare disease that can affect the pediatric hand. This condition often causes a finger mass, deformity, pain and possible pathologic fractures, and has been associated with malignant transformation to chondrosarcoma. The aim of our study is to describe the long-term sequela of multiple enchondromatosis of the hand in the pediatric population, specifically the rates of malignant transformation, tumor recurrence, rates of pathologic fracture, and phalangeal growth arrest. Methods: We examined 15 pediatric patients who were treated in our institute with a total of 127 phalanges and metacarpals lesions. Only patients with follow-up of at least 4 years were included. We retrospectively reviewed patients’ chart and hand radiograph for symptoms including pathologic fractures, indications for surgery, and postoperative complications including tumor recurrence, and malignant transformation. We assessed phalangeal growth arrest with radiographs and normalized phalangeal growth charts. Results: Mean age of diagnosis was 5.8 years and mean follow-up time was 15.4 years. Pathologic fractures were common at 46% of pediatric patients, but ceased to occur once reaching adulthood. Outcomes of pathologic fractures were excellent, regardless of treatment. Malignant transformation occurred in 1 patient and did not occur during childhood. A total of 80% of patients and 29% of lesions underwent surgical treatment of curettage and bone graft for the lesion, yet recurrence was common and affected 33% of treated patients. Phalangeal growth arrest was the most common long-term sequela and affected 11% of phalanxes and metacarpals. This sequela was significantly more prevalent in patients who had surgical excision of the tumor. Conclusions: Our findings reassure that malignant transformation of enchodromatosis of the hand is unlikely in the pediatric population. Pathologic fracture is common, but has excellent outcomes. When considering surgery, parents should be counseled about the possibility of phalangeal growth arrest and recurrence of the lesion. Type of Study/Level of Evidence: Level IV—therapeutic.

Background: The etiology of multifocal osteonecrosis is not definitively known; however, hypercoagulable state is a very plausible cause. Methods: We present an unusual case of a 12-year-old boy with a history of Legg-Calve-Perthes disease presenting with right wrist pain who was subsequently diagnosed with Kienbock’s disease. The finding of multifocal osteonecrosis prompted testing for a hypercoagulable state that was positive for Factor V Leiden thrombophilia. A thorough literature review using Medline database was conducted to investigate associations between inherited hypercoagulable states and multifocal osteonecrosis. Results: Our literature review identified 2 similar cases of multifocal osteonecrosis associated with a hypercoagulable disorder in adult patients. There were no reports among the pediatric patient population. Meta-analysis has demonstrated a potential link between Legg-Calve-Perthes disease and Factor V Leiden thrombophilia. Conclusions: This study offers further evidence to support the theory that multifocal osteonecrosis may be linked to a hypercoagulable state. Patients presenting with multifocal osteonecrosis should undergo screening for hypercoagulable states. Further investigation is needed to ascertain the potential benefit of prophylactic anticoagulation in patients with a known hypercoagulable state and multifocal osteonecrosis.