Hallux anatomy: much ado about shoes-an attempt to prove that constrictive V-shaped toe-box shoes deform the hallux.

PURPOSE: A question still remains as to whether constrictive toe-box shoes (TBS) cause disability only due to pain on pressure points or if they can cause permanent changes in the hallux anatomy. The aim of this study is to compare the hallux morphology in 3 groups classified according to their use of constrictive or open TBS. METHODS: 424 patients were classified into 3 groups: group A used open TBS daily; group B used constrictive TBS daily; group C used both open and constrictive TBS. Hallux's angles, presence of exostoses and shape of the distal phalanx (DP) were analyzed on dorsoplantar weight-bearing radiographs and compared amongst groups. RESULTS: The intermetatarsal (IMA), metatarsophalangeal (MTPA), DASA, PASA, interphalangeal (IPA), obliquity (AP1), asymmetry (AP2) and joint deviation (JDA) angles for group A were 10°, 8°, 5°, 4°, 9°, 3°, 5°, 3°; for group B were 9°, 19°, 5°, 6°, 12°, 2°, 8°, 2°; and for group C were 10°, 10°, 4°, 4°, 12°, 3°, 8°, 1°. Only the differences in the MTPA, IPA and AP2 were statistically significant (p < 0.05). The prevalence of exostoses on the tibial side of the DP was 22, 36, and 29% in groups A, B and C, respectively (p < 0.05). We found similar distributions of the different DP shapes in the three groups. CONCLUSIONS: Our results suggest that the use of constrictive TBS, even if used only occasionally, could change hallux anatomy from a young age increasing MTPA, IPA and AP2. Moreover, we have found that DP exostoses are present as a "normal variation" in patients who wear an open TBS, but their prevalence is higher in those wearing constrictive toe-box shoes. This could be due to a reactive bone formation secondary to the friction caused by the inner border of the shoe. LEVEL OF CLINICAL EVIDENCE: 3.

Proximal tibiofibular joint changes after closed-wedge high tibial osteotomy. Are they relevant?

BACKGROUND: There is some controversy about how the proximal tibiofibular joint (PTFJ) capsulotomy changes PTFJ anatomy in closed-wedge high tibial osteotomy (CW-HTO) and about how this affects ankle and knee mobility and the onset of lateral knee pain. The aim of this study is to evaluate changes in PTFJ after CW-HTO, and its possible clinical significance. METHODS: This study includes 50 patients who underwent CW-HTO with tibiofibular capsulotomy from 2000 to 2018 in our hospital. A clinical evaluation was conducted to evaluate pain location. The degrees of osteoarthritis and the proximal fibular subluxation were evaluated on radiographs. A dynamic analysis of the PTFJ was also performed comparing proximal fibular head subluxation on anteroposterior knee radiographs with the ankle placed in neutral position and dorsiflexed. RESULTS: The clinical evaluation revealed that two patients had a sore scar, five had pain on the PTFJ with manual compression, and none referred lateral compartment pain. The radiological analysis revealed an average proximal subluxation of the fibular head after the osteotomy of 9.64 (range: 0-29) mm, which was greater in oblique PTFJ (p < 0.05). After the surgery, all the patients developed some degree of PTFJ arthritis. There was no correlation between lateral pain and proximal fibular subluxation, tibiofibular arthritis, or lateral compartment arthritis. The dynamic analysis revealed no significant changes. CONCLUSIONS: After CW-HTO all the patients developed proximal subluxation of the fibular head and a variable degree of PTFJ osteoarthritis, but these changes seem to be unrelated with lateral knee pain.

Feasibility of open and percutaneous corrective osteotomies of the second phalanx of the great toe: An approach on a cadaveric model.

BACKGROUND: Having had a previous experience of 4 open F2 osteotomies to correct interphalangeal hallux valgus, the aim of this study was to test the efficacy of a percutaneous approach for this correction. METHODS: 3 open and 12 percutaneous F2 osteotomies in 15 cadaver feet were performed. Interphalangeal (IPH), F2 asymmetry (AF2) and joint deviation (JD) angles were measured on radiographs. The operated great toes were anatomically analyzed looking for possible lesions to surrounding tissues. RESULTS: Mean IPH decreased from 10.7° to 2.9°, AF2 from 7.8° to 1°, and JD from 1.4° to 0.5°. Damage to the hallux extensor tendon was detected in 1 foot and a nail bed lesion was detected in 1 case, both operated percutaneously. CONCLUSIONS: F2 Valgus deformity can be corrected using open or percutaneous osteotomy. The authors consider the open correction worthwhile because percutaneous techniques may damage surrounding tissues and the incision length difference is minor. LEVEL OF CLINICAL EVIDENCE: 3.

Evaluation of driving skills after anterior cruciate ligament reconstruction with hamstring autograft.

BACKGROUND: There are no well-established guidelines for safe driving after injury or surgical treatment. The purpose of this study was to assess the aptitude to regain driving skills and brake reaction abilities after anterior cruciate ligament (ACL) surgery. METHODS: This study compared the driving abilities and skills at four to six weeks after surgery of 31 patients who underwent ACL reconstruction with hamstring autograft with 31 healthy volunteers. Multiple variables, including pedestrian impact, car crash, red traffic light violations, visual reaction time, and other driving abilities were measured with a validated driving simulator. RESULTS: There was no statistically significant between-group difference with respect to skill, driving ability, and brake reaction times (P > 0.05). The differences between right and left knees were also not statistically significant (P > 0.05). However, patients with a right ACL reconstruction had a higher number of collisions with fixed objects (2.82 vs. 1.84, P = 0.239) and pedestrian impacts (0.23 vs. 0.00 P = 0.221), and had slower brake reaction times (585.69 vs. 456.02 ms, P = 0.069). The Tegner score was similar in each group (7.19 in ACL reconstruction group vs. 6.8 in control group, P = 0.092) and the Lysholm score improved as compared with the presurgical measurement (53.48 vs. 89.61, P < 0.001). CONCLUSIONS: Anterior cruciate ligament surgery with hamstring autograft did not result in a decrease in driving performance and safety at four to six weeks after surgery with respect to skill, ability to drive, and brake response time.

Hypoxia and Reactive Oxygen Species Homeostasis in Mesenchymal Progenitor Cells Define a Molecular Mechanism for Fracture Nonunion.

Fracture nonunion is a major complication of bone fracture regeneration and repair. The molecular mechanisms that result in fracture nonunion appearance are not fully determined. We hypothesized that fracture nonunion results from the failure of hypoxia and hematoma, the primary signals in response to bone injury, to trigger Bmp2 expression by mesenchymal progenitor cells (MSCs). Using a model of nonstabilized fracture healing in transgenic 5'Bmp2BAC mice we determined that Bmp2 expression appears in close association with hypoxic tissue and hematoma during the early phases of fracture healing. In addition, BMP2 expression is induced when human periosteum explants are exposed to hypoxia ex vivo. Transient interference of hypoxia signaling in vivo with PX-12, a thioredoxin inhibitor, results in reduced Bmp2 expression, impaired fracture callus formation and atrophic-like nonunion by a HIF-1α independent mechanism. In isolated human periosteum-derived MSCs, BMP2 expression could be induced with the addition of platelets concentrate lysate but not with hypoxia treatment, confirming HIF-1α-independent BMP2 expression. Interestingly, in isolated human periosteum-derived mesenchymal progenitor cells, inhibition of BMP2 expression by PX-12 is accomplished only under hypoxic conditions seemingly through dis-regulation of reactive oxygen species (ROS) levels. In conclusion, we provide evidence of a molecular mechanism of hypoxia-dependent BMP2 expression in MSCs where interference with ROS homeostasis specifies fracture nonunion-like appearance in vivo through inhibition of Bmp2 expression. Stem Cells 2016;34:2342-2353.

Reconstruction of the extensor mechanism with fresh-frozen tendon allograft in total knee arthroplasty.

PURPOSE: Patellar tendon rupture after total knee replacement is a rare and highly limiting injury with multifactorial aetiology. Many reconstruction techniques have been described with not very predictable results. The use of allografts has been accepted as a suitable solution. METHODS: A series of seven patients with patellar tendon rupture treated with fresh-frozen tendon allograft reconstruction after knee arthroplasty is presented. RESULTS: Median follow-up is 25 months (20-31). Functional assessment improved, and the knee society score and knee functional score improved from 26 and 16 to 82 and 55, respectively. Median extension lag was 5° (0°-20°), with a median range of motion of 95° (70-100). Radiological study showed a rise of the patella of 22.26 mm. CONCLUSION: The use of fresh-frozen allografts as a solution to patellar tendon ruptures after knee arthroplasty seems to provide acceptable results. Increased patellar height does not seem to affect functionality. LEVEL OF EVIDENCE: Case series, Level IV.

Symptomatic medial exostosis of the great toe distal phalanx: a complication due to over-correction following akin osteotomy for hallux valgus repair.

UNLABELLED: The authors present the case of a 54-year-old female who developed a painful compression lesion localized to the medial aspect of the base of the distal phalanx of the great toe as a complication of hallux valgus surgery. Preoperative radiographic evaluation of the patient's foot revealed the first ray to be longer than the second, a 12 degrees first intermetatarsal angle, a 33 degrees hallux abductus angle, and an exostosis at the medial aspect of the base of the hallux that was not considered by the surgeon to be important. Correction of the hallux valgus deformity was performed with a combination of scarf and Akin osteotomies, and the intermetatarsal and hallux abductus angles reduced to 2 degrees and 8 degrees , respectively. By 2 months postoperative, the patient was complaining of pain at the medial aspect of the distal phalanx of the hallux associated with shoe pressure. The pain correlated both clinically and radiologically with the exostosis at the base of the distal phalanx, and had become symptomatic only after the hallux had been operatively realigned. At 6 months postoperative, percutaneous exostectomy was undertaken to remove the exostosis. Pain relief was complete, thereafter, and after 2 years of postoperative follow-up the patient remained pain free. The clinical importance of a medial exostosis localized to the base of the distal phalanx of the hallux must be taken into consideration whenever hallux valgus correction is undertaken, and this is particularly important whenever an Akin osteotomy is being considered. LEVEL OF CLINICAL EVIDENCE: 4.