First tarsometatarsal arthrodesis for severe hallux valgus using the tension band principle - Technical tip and case series.

BACKGROUND

Hallux valgus (HV) is a common foot pathology. Severe HV in the presence of Tarsometatarsal joint (TMTJ) instability is often managed with arthrodesis of the 1st TMTJ. There are concerns regarding non-union and malunion (particularly the early loss of inter-metatarsal angle correction before complete arthrodesis). We report our medium-term results of a small series of patients that underwent an evolved surgical technique utilising orthogonal staples and a transverse suture button fixation to address biomechanical concerns with traditional Lapidus arthrodesis.

METHODS

A retrospective study of a consecutive series of patients who underwent this surgical technique between February 2017 and May 2022. Clinical outcomes were validated through Patient-reported outcomes measures (PROMS); EuroQol-5 Dimension (EQ-5D) and Manchester-Oxford Foot Questionnaires (MOXFQ). Radiographic parameters (hallux valgus (HVA), intermetatarsal (IMA), distal metatarsal articular angle (DMAA)) were assessed. Union of the arthrodesis and complications were recorded.

RESULTS

During the study period, 9 feet underwent the procedure. Radiographic data was available for all nine and PROMS data for seven (77.8%). Significant improvement occurred in all radiographic deformity parameters at mean 6-month follow-up. Mean ± standard deviation correction calculated preoperatively as HVA 40.2°, IMA 19.3° and DMAA 15.8°, corrected to HVA 15.4°, IMA 5.8° and DMAA 5.9° postoperatively. (HVA; P < 0.001, IMA; P < 0.001, DMAA; P < 0.001) Clinical PROMs at mean follow-up of 2 years were MOXFQ 34.4 ± 25.2, EQ-5D-5 L 0.819 ± 0.150 and VAS pain 13.6 ± 13.6. There were no cases of non-union, Tibialis anterior tendon irritation or hallux varus. Complications included first MTPJ stiffness in one case and CRPS and dorsiflexion malunion of the first ray in another patient.

CONCLUSION

This preliminary study of the procedure used in this series confirm this is a safe surgical technique to address severe HV with a low rate of non-union and significant radiographic improvements. A larger patient dataset is needed to evaluate this procedure robustly.