Anatomy of the Plantar Intermetatarsal Tunnel: A Cadaveric Study.

The contents of the plantar intermetatarsal tunnel (PIMT) and the relationship between the common plantar interdigital nerve (CPIN) and the PIMT were recorded. The width of the PIMT was measured at the metatarsal neck (MTN), metatarsophalangeal (MTP) joint and the base of the proximal phalanx (BPP). The length of the deep transverse metatarsal ligament (DTML), the PIMT and the intracapsular ligament (ICL) were also measured. The PIMT was revealed to be a narrow osseofibrous tunnel divided into 3 segments by the DTML: the distal section, the area under the DTML (middle) and the proximal section. The length of the middle section was 12.77 mm in the second intermetatarsal (IM) space and 10.18 mm in the third IM space. The lengths of the distal sections were 15.52 and 14.95 mm in the second and third IM spaces, respectively. There was some soft tissue between the CPIN and PIMT, and the CPIN was observed not to glide freely within the tunnel. The widths of the PIMT at the MTN, MTP joint and BPP were respectively 2.87, 2.56, and 3.42 mm in the second IM space and 3.10, 2.68 and 3.61 mm in the third IM space. The ICL lies between the capsules of the MTP joint, and the length of the ICL was 2.76 and 3.03 mm in the second and third IM spaces, respectively. The PIMT was found to be a complex spatial structure, and the ICL might prevent the CPIN from being squeezed into the IM space.

Anatomy of the Distal End of Flexor Digitorum Longus Tendon and Percutaneous Release Technique: A Cadaveric Study.

BACKGROUND: The transfer of flexor-to-extensor is widely used to correct lesser toe deformity and joint instability. The flexor digitorum longus tendon (FDLT) is percutaneously transected at the distal end and then routed dorsally to the proximal phalanx. The transected tendon must have enough mobility and length for the transfer. The purpose of this study was to dissect the distal end of FDLT and identify the optimal technique to percutaneously release FDLT. METHODS: Eight fresh adult forefoot specimens were dissected to describe the relationship between the tendon and the neurovascular bundle and measure the width and length of the distal end of FDLT. Another 7 specimens were used to create the percutaneous release model and test the strength required to pull out FDLT proximally. The tendons were randomly released at the base of the distal phalanx (BDP), the space of the distal interphalangeal joint (SDIP), and the neck of the middle phalanx (NMP). RESULTS: At the distal interphalangeal (DIP) joint, the neurovascular bundle begins to migrate toward the center of the toe and branches off toward the center of the toe belly. The distal end of FDLT can be divided into 3 parts: the distal phalanx part (DPP), the capsule part (CP), and the middle phalanx part (MPP). There was a significant difference in width and length among the 3 parts. The strength required to pull out FDLT proximally was about 168, 96, and 20 N, respectively, for BDP, SDIP, and NMP. CONCLUSION: The distal end of FDLT can be anatomically described at 3 locations: DPP, CP, and MPP. The tight vinculum brevis and the distal capsule are strong enough to resist proximal retraction. Percutaneous release at NMP can be performed safely and effectively. CLINICAL RELEVANCE: Percutaneous release at NMP can be performed safely and effectively during flexor-to-extensor transfer.

Surgical Anatomy of the Medial Cuneiform (Cotton) Osteotomy.

BACKGROUND: The Cotton osteotomy, or dorsal-opening wedge osteotomy of the medial cuneiform (MC), is used to address medial column alignment to restore the static-triangle of support. There are many described techniques regarding the incision and osteotomy. Successful completion of the osteotomy requires knowledge of the anatomy, particularly the location of the medial dorsal cutaneous nerve (MDCN). This study describes the relationship between MDCN, tibialis anterior, extensor-hallucis-longus tendon, and ligamentous attachments to the MC. A technique to determine a safe location for the osteotomy is also described. METHODS: Twelve fresh-frozen adult foot specimens were used for this study (7 male and 5 female). The MDCN and its branches were dissected and its relationship with the MC was documented. Osteotomy tilt angle and relationship to structures around the MC were measured. RESULTS: MDCN traveled medially and distally over the dorsum of the MC, and a small branch to the MC was observed. The tilt angle was 80.1 ±1.4 degrees. There was no significant difference between the distance from the distal-articular surface to the midline of the cuneiform and to the interosseous ligament (P = .69), or between the distance from the distal-articular surface to the second tarsometatarsal joint and to the origin of the Lisfranc ligament (P = .12). CONCLUSIONS: The dorsal-medial-oblique incision effectively protected MDCN and the MC. We believe the osteotomy should be performed in the safe zone to maintain the stability of the opening wedge. CLINICAL RELEVANCE: The dorsal-medial-oblique incision could reduce the risk of injury to the MDCN and the tibialis-anterior tendon.

Arthroscopic treatment combined with the ankle stabilization procedure is effective for sinus tarsi syndrome in patients with chronic ankle instability.

PURPOSE: This study aimed to investigate the results of arthroscopic treatment combined with ankle stabilization procedure for sinus tarsi syndrome (STS) in patients with chronic ankle instability (CAI). METHODS: A total of 57 patients (31 males and 26 females, average age 29.9 ± 8.4 years ranging from 15 to 52 years) with STS and CAI who accepted operation from 2013 to 2015 were included in this retrospective study. Surgical procedures included thorough tarsal sinus debridement and repair or reconstruction of lateral ankle ligaments according to the quality of ligaments. American Orthopedic Foot and Ankle Society (AOFAS) score, Karlsson score, and Tegner score were evaluated preoperatively and at final follow-up. RESULTS: All the patients accepted thorough debridement of tarsal sinus. Of these, 53 patients (93.0%) had an arch structure between the posterior subtalar joint and the middle subtalar joint. Further, 54 patients accepted lateral ankle ligament repair, and 3 patients accepted ligament reconstruction. A total of 40 patients were followed up with an average time of 30.7 months. The modified AOFAS score increased from 62.5 (27-90) to 93 (67-100), the Karlsson score increased from 57 (30-82) to 90 (55-100), and the Tegner score increased from 1 (1-3) to 5 (1-8). CONCLUSIONS: Arthroscopic treatment combined with the ankle stabilization procedure could get satisfactory results for STS in patients with CAI. The arch structure composed by medial calcaneal component of the medial root of the inferior extensor retinaculum (MCC) might contribute to the pathological mechanism of STS. LEVEL OF EVIDENCE: IV.

A Long-Term Study of the Effect of Subtalar Arthrodesis on the Ankle and Hindfoot Joints.

BACKGROUND: Subtalar arthrodesis is a common therapy for subtalar joint disorders. In this article, we evaluate the effect of subtalar arthrodesis on the ankle and hindfoot joints. METHODS: Fifty patients (33 men and 17 women) underwent subtalar arthrodesis between January 1, 1996, and August 31, 2011. The 36-item Short-Form Health Survey and American Orthopaedic Foot and Ankle Society ankle hindfoot scores were used for clinical evaluation. Radiographic analysis included assessment of degenerative changes and ankle and hindfoot joint function in the frontal and sagittal planes. RESULTS: Thirty-seven patients (27 men and 10 women; mean age, 42.6 years) were followed up for an average of 9.2 years (range, 2-17 years). The mean ± SD 36-item Short-Form Health Survey score improved from 30.21 ± 7.19 before surgery to 78.50 ± 12.23, and the American Orthopaedic Foot and Ankle Society ankle hindfoot score increased from 50.32 ± 12.39 to 73.14 ± 15.44. Degenerative changes in the talonavicular, calcaneocuboid, metatarsocuboid, and ankle joints occurred. The talar-vertical angle was positively related to the tibial-plantar minimal angle (affected side: r = 0.56; P < .01; healthy side: r = 0.46; P < .01). The difference in hindfoot height is positively related to the difference in tibial-plantar minimal angle (r = 0.54; P < .01). CONCLUSIONS: Subtalar arthrodesis is effective treatment for subtalar joint disease but could induce joint degeneration and ankle joint motion limitation related to talar declination and hindfoot height.

A retrospective clinical study on 37 subtalar arthrodesis patients of nine years follow-up.

BACKGROUND: Subtalar arthrodesis is a common therapy for subtalar joint disorders. In this article, we evaluate the effect of subtalar arthrodesis on the ankle and hindfoot joints. METHODS: Fifty patients (33 men and 17 women) underwent subtalar arthrodesis between January 1, 1996, and August 31, 2011. The 36-item Short-Form Health Survey and American Orthopaedic Foot and Ankle Society ankle hindfoot scores were used for clinical evaluation. Radiographic analysis included assessment of degenerative changes and ankle and hindfoot joint function in the frontal and sagittal planes. RESULTS: Thirty-seven patients (27 men and 10 women; mean age, 42.6 years) were followed up for an average of 9.2 years (range, 2-17 years). The mean ± SD 36-item Short-Form Health Survey score improved from 30.21 ± 7.19 before surgery to 78.50 ± 12.23, and the American Orthopaedic Foot and Ankle Society ankle hindfoot score increased from 50.32 ± 12.39 to 73.14 ± 15.44. Degenerative changes in the talonavicular, calcaneocuboid, metatarsocuboid, and ankle joints occurred. The talar-vertical angle was positively related to the tibial-plantar minimal angle (affected side: r = 0.56; P < .01; healthy side: r = 0.46; P < .01). The difference in hindfoot height is positively related to the difference in tibial-plantar minimal angle (r = 0.54; P < .01). CONCLUSIONS: Subtalar arthrodesis is effective treatment for subtalar joint disease but could induce joint degeneration and ankle joint motion limitation related to talar declination and hindfoot height.

Cluster of differentiation 44- and octamer-binding transcription factor-4-positive stem-like osteosarcoma cells involved in tumor development.

Osteosarcoma (OS) is an aggressive primary bone cancer that usually affects children and young adolescents. Previous studies have demonstrated the implications of a small sub-population of cancer stem cells on treatment failure and tumor recurrence. The present study analyzed the characteristic features of the stem-like cells within the human OS-55 cell line. It was identified that 2.3% of the OS-55 cells were cancer stem-like side population (SP) cells. Following treatment with verapamil, the population of SP cells was reduced to 0.7%. The sphere formation assay revealed that the OS cells were able to rapidly form tumor spheres (also known as sarcospheres). Immunofluorescence analysis identified that the OS-55 cells expressed the cluster of differentiation 44, octamer-binding transcription factor-3/4A and Nanog stem cell surface markers. The results of the present study suggest that, as with other tumors, OS also contains a sub-population of cancer stem-like cells, which may have important implications in cancer diagnosis and treatment.

Serum levels of 25-hydroxyvitamin D and functional outcome among postmenopausal women with hip fracture.

OBJECTIVE: The main objective of the current study was to assess the distribution and its prognostic value of serum 25-hydroxyvitamin D (25[OH] D) levels assessed at admission in Chinese postmenopausal women with hip fracture. METHODS: From January 1, 2012 to December 31, 2013, all postmenopausal women with first-ever hip fracture were recruited to participate in the study. Serum 25[OH] D levels were measured at admission. The functional evaluation at the time of discharge was performed by the Barthel Index (BI). The prognostic value of 25[OH] D to predict the functional outcome within discharge was analyzed by logistic regression analysis, after adjusting for the possible confounders. RESULTS: In our study, 261 patients were included and assessed. In the 76 patients with an unfavorable functional outcome, serum 25(OH) D levels were lower compared with those in patients with a favorable outcome [11.8(IQR, 9.9-16.1) ng/ml; 16.8(IQR, 13.6-21.4) ng/ml, respectively; P<0.0001]. In multivariate analysis, there was an increased risk of unfavorable outcome associated with serum 25(OH) D levels ≤ 20 ng/ml (OR 5.24, 95%CI: 3.11-8.15; P<0.0001) after adjusting for possible confounders. CONCLUSIONS: Our data support an association between serum 25[OH] D levels and prognosis in Chinese postmenopausal women with hip fracture.