The posterior malleolus component of a fracture of the ankle is important, yet often overlooked. Pre-operative CT scans to identify and classify the pattern of the fracture are not used enough. Posterior malleolus fractures are not difficult to fix. After reduction and fixation of the posterior malleolus, the articular surface of the tibia is restored; the fibula is out to length; the syndesmosis is more stable and the patient can rehabilitate faster. There is therefore considerable merit in fixing most posterior malleolus fractures. An early post-operative CT scan to ensure that accurate reduction has been achieved should also be considered.

Cite this article: Bone Joint J 2017;99-B:1413–19.

Introduction: A long first metatarsal is a recognized contributing factor to the development of hallux rigidus. It is possible to identify a sub-group of patients with a long first metatarsal and early hallux rigidus. L.S. Barouk & P. Barouk have recently described the use of a modified Weil shortening osteotomy for the treatment of this sub-group of patients. The purpose of the study was to evaluate the early results of a modified Weil’s osteotomy of the first metatarsal in selected patients with hallux rigidus.

Materials and Methods: Fifteen patients with mild to moderate OA of the first MTP joint in whom the first metatarsal was at least as long as the second underwent a shortening and plantar-displacing Weil’s osteotomy.

Results: At a minimum follow-up of six months all patients’ symptoms improved dramatically and the range of motion was improved in all cases. One patient, a 19 year old professional footballer, developed a stress fracture of the second metatarsal which went on to heal and he was able to return to professional football. One patient developed transfer metatarsalgia. There were no cases of AVN and all patients were satisfied with the outcome of surgery.

Discussion: There are many treatment strategies for hallux rigidus. Fusion surgery provides excellent pain relief but joint preserving surgery is preferable. Cheilectomy is reliable but has a significant failure rate. Joint replacements remain experimental. Debridement of the joint in combination with longitudinal decompression of the first MTPJ provides greater range of motion than cheilectomy alone in the subgroup of patients who have a long first metatarsal.

Conclusions: These early results suggest that in selected individuals with hallux rigidus associated with a long first metatarsal, a modified Weil’s osteotomy can improve the range of motion of the first MTP joint and result in significant pain relief.

Inversion injuries of the ankle are common and most are managed adequately by functional treatment. A significant number will, however, remain symptomatic.

Synovial impingement is one cause of continuing pain. This condition is often difficult to diagnose because the physical signs and investigations are non-specific. If the diagnosis is made, treatment by arthroscopic debridement has been shown to be highly effective. Our aim was to describe a new physical sign to help in the diagnosis of anterolateral synovial impingement in the ankle.

A cadaver dissection demonstrated the anatomical basis for the physical sign and a prospective clinical study involving 73 patients showed that the lateral synovial impingement test had a sensitivity of 94.8% and a specificity of 88%.

We describe the test and conclude that this physical sign will be of use to practitioners treating patients with chronic pain in the ankle after injury.

We describe a patient who sustained a displaced isolated intra-articular fracture of the distal ulna, causing limitation of rotation of the forearm. The extent of displacement of the fracture which was not evident on plain radiographs was revealed by CT. The fracture was reduced and internally fixed using a standard technique applicable to the fixation of fractures of the radial head. Full movement was restored. An isolated injury to the distal ulna is rare and requires careful clinical and radiological assessment.

Ligamentous injury of the tarsometatarsal joint complex is uncommon but disabling. Injuries to individual ligaments can be visualised with MRI. The relative mechanical contribution of the three ligaments of the second TMTJ is unknown.

Methods

The second and third metatarsals and the first cuneiform were dissected from twenty pairs of cadaveric feet.

In group I, seven pairs were submaximally loaded to determine stiffness with the dorsal, plantar, and Lisfranc ligaments intact. One of each pair underwent sectioning of the dorsal ligament and was then loaded to failure. In the contralateral specimen both plantar and Lisfranc ligaments were divided before retesting.

In group II all 13 pairs underwent dorsal ligament excision and stiffness determination. One of each pair was randomly assigned to undergo sectioning of the plantar ligament, the other sectioning of the Lisfranc ligament, before retesting.

Results and Conclusions

The Lisfranc ligament is stronger and stiffer than the plantar ligament. The dorsal ligament is weaker than the Lisfranc/plantar complex. This suggests that ligamentous injuries of the second tarsometatarsal joint may be considered stable if the Lisfranc ligament is intact – even if the other two ligaments are disrupted. If the Lis-franc ligament is injured then the complex is less stiff and may be unstable.

The Mayo Conservative uncemented stem (Zimmer, Warsaw, USA) is designed to conserve proximal bone stock by virtue of a minimal neck resection and to maintain proximal femoral stress transfer, thereby reducing problems associated with stress shielding.

This study was performed to evaluate proximal femoral strain after implantation of the Mayo stem, in cadaveric femora.

Eight fresh-frozen cadaveric femora (each selected at random from within a pair) of known bone mineral density were prepared and coated with photoelastic materials (Measurements Group, Raleigh NC). Strain patterns of the intact bone were determined using a reflection polariscope, and recorded photographically, while under load. Quantitative measurements were taken from set points of the proximal femur. The femoral head was then replaced using a Mayo femoral prosthesis. Under the same loading conditions strain patterns were re-examined and measurements taken from the same set points.

The strain patterns following insertion of the Mayo stem closely matched those seen in intact femora except in two areas. Strain was reduced in the region of the lesser trochanter (53% of normal), although more proximal than this strain in the neck was closer to intact values (78% of normal). Previous studies have found that implantation of diaphyseal press fit stems in particular have led to significant reductions in shear strain values in the calcar region and distally along the medial border of the femur.

This study documents the strain pattern in the proximal femur after implantation with a new “conservative” short stem cementless prosthesis. The hypothesis that the Mayo femoral stem maintains proximal femoral stress transfer and may thus prevent stress shielding in vivo remains to be proven, but is supported by the results of this study.

Manipulation of the metatarsophalangeal joint and injection with steroid and local anaesthetic are widely practised in the treatment of hallux rigidus, but there is little information on the outcome. We report the results of this procedure carried out on 37 joints, with a minimum follow-up of one year (mean, 41.2 months). Patients with mild (grade-1) changes gained symptomatic relief for a median of six months and only one-third required surgery. Two-thirds of patients with moderate (grade-2) disease proceeded to open surgery. In advanced (grade-III) hallux rigidus, little symptomatic relief was obtained and all patients required operative treatment. We recommend that joints are graded before treatment and that manipulation under anaesthetic and injection be used only in early (grades I and II) hallux rigidus.

Most techniques described for the correction of hallux valgus require exposure of the distal aspect of the first metatarsal. A dorsomedial incision is often recommended. Texts counsel against damaging the dorsal digital nerve, as a painful neuroma is an unwelcome surgical complication.

Our study on cadavers aimed to investigate the anatomy of the dorsomedial cutaneous nerve in the metatarsophalangeal region, with special reference to surgical incisions. A constant, previously unrecognised branch of the nerve was identified. This branch is likely to be damaged if a dorsomedial approach is used. It is recommended that a mid-medial incision be used instead, i.e. at the junction of the plantar and dorsal skin.