Hallux rigidus was first described in 1887. Many aetiological factors have been postulated, but none has been supported by scientific evidence. We have examined the static and dynamic imbalances in the first metatarsophalangeal joint which we postulated could be the cause of this condition. We performed a finite-element analysis study on a male subject and calculated a mathematical model of the joint when subjected to both normal and abnormal physiological loads.

The results gave statistically significant evidence for an increase in tension of the plantar fascia as the cause of abnormal stress on the articular cartilage rather than mismatch of the articular surfaces or subclinical muscle contractures. Our study indicated a clinical potential cause of hallux rigidus and challenged the many aetiological theories. It could influence the choice of surgical procedure for the treatment of early grades of hallux rigidus.

Introduction: The foot is a very complex structure acting as the platform for all gait patterns. At present, little is known about the exact biomechanics of the foot due to the difficulties in modeling all of the components of the foot accurately. This has made it virtually impossible to develop a complete understanding of the aetiology of many diseases of the foot including hallux rigidus. We hypothesize that sagittal plane incongruency of the rotation of the 1^st Metatarsophalangeal Joint (MTPJ), or an increase in the tension of the intrinsic plantar flexors is responsible for the development of hallux rigidus.

Materials & Methods: Ground reaction forces and kinematic data from gait analysis together with anthropometric data from MRI scans of a 24 y.o. female were used to create a Mimics model of the articulation of a normal 1st MTPJ during a gait cycle. The centre of rotation was calculated by triangulating the articular surfaces. Finite element analysis was performed on the model and on similar models with the hypothesized;

joint incongruency,

Results: The results demonstrated a significant increase in the peak stresses, contact areas and stress distributions between the incongruent models compared to the congruent models.

Discussion: To the best of our knowledge this is the most accurate FE model of the 1st MTPJ calculated. Hallux Rigidus is a very common forefoot disorder, with multiple etiologies and treatments advocated. This model demonstrates that an increased tension in the plantar flexors results in a reduced ROM with increased contact stresses on the joint surface.

Conclusion: While it is known Hallux Rigidus has a multi-factorial etiology, the authors feel the above study demonstrates an important inherent etiology.

Background: First Metatarsophalangeal joint (MTP) arthrodesis is commonly performed for hallux valgus with an arthritic joint, however previous studies have recommended that this should be combined with another procedure to correct the hallux valgus when the intermetatarsal angle is enlarged. We propose that an arthrodesis of the first MTP joint with a soft tissue release produces a significant correction of the intermetatarsal angle in such a group of patients avoiding the need for a concomitant procedure to change the intermetatatarsal angle.

Patients and Methods: The charts and radiographs of 20 patients who had an arthrodesis of the first MTP joint were retrospectively reviewed. All 20 patients were female with a mean age of 54.2 years (range 42–78 years). The intermetatarsal (IMT) angles were measured by two individuals independently. These were measured on a weight-bearing pre-operative film and a weight-bearing 6-week post-operative film. Fusions were performed using either the Hallu-S® plate or two crossed screws. A Student “t” test was performed on the change of the IMT angle and also on the inter-observer variations for the same.

Results: The mean pre-operative IMT angle was 16.85° (range 12–30°). The mean post-operative IMT angle was 10.6° (range 6–20°). The mean change in the IMT angle was 6.25° (range 2–12°). This change of the IMT angle was statistically significant – p< 0.0001 – Student “t” test. There was no significance in the inter-observer difference (p> 0.5) note in 6 radiographs with a mean of 1.3° (range 1–2°).

Conclusion: This is the first study to show that performing an arthrodesis of the first MTP joint with soft tissue release in patients with hallux valgus and degenerate first MTP joint will significantly correct the IM angle. Therefore, this alleviates the need for performing another procedure on these patients.

We assessed the long-term outcome of open debridement for the treatment of anterior impingement of the ankle in 27 patients. By using preoperative radiographs to group patients according to both the McDermott and the van Dijk scoring system, we assessed the accuracy of these classifications in predicting outcome. The Ogilvie-Harris scoring system, a visual analogue scale of patient satisfaction, the time to return to full activities, and the ability to return to sports determined the clinical outcome. Follow-up radiographs were used to assess the recurrence of osteophytes. We also assessed the incidence of talar osteochondral lesions at surgery.

At a mean follow-up of 7.3 years, 23 of 25 patients (92%) without joint-space narrowing had a good or excellent result. Improvement in the Ogilvie-Harris score was seen in all patients. In athletes, 19 of 24 (79%) were able to return to sports at the same level. Two patients with preoperative joint-space narrowing had a poor result.

Osteophytes usually recurred and most patients did not feel that the range of dorsiflexion returned to normal, but symptomatic relief allowed most to return to high-level sport.

Our results for non-arthritic joints suggest that this is a safe and successful procedure.

It has been well documented that leg length discrepancy can be associated with back, knee and hip problems. Less is known about the effect on the foot. The effect of a simulated leg length discrepancy on foot loading patterns and gait cycle times in normal individuals was investigated.

Thirty feet of normal volunteers were evaluated using a ‘Musgrave Footprint Computerised Pedobarograph System’. Leg length discrepancy was simulated using flexible polyurethane soles of 1 to 5cm thickness, secured to the sole of a sandal worn on the opposite foot. Recordings of foot pressures and load were made barefoot (control) and then recordings were taken with simulated leg length discrepancies of 1 to 5cm. As leg length discrepancy increased, the total loading on the foot increased from 35. 31 to 37. 99 kg/cm²/sec, the forefoot loading increased from 15. 58 to 19 kg/cm²/sec, whereas hindfoot loading remained the same. Further analysis of forefoot loading revealed that all subjects except for female middle loaders demonstrated increased hallux loading as the leg length discrepancy increased (p< 0. 0001). Analysis of gait cycle time with increasing leg length discrepancy showed that the contact phase of gait decreased from a mean of 22% to 13% (p< 0. 0001), the midstance phase remained the same, whereas the propulsion phase increased from 44% to 50% (p< 0. 003).

This study demonstrates for the first time that leg length discrepancy has manifest changes in the foot. When prescribing orthotics to address leg length discrepancy, orthopaedic surgeons should consider attempts to relieve the increased pressure on the 2nd and 3d metatarsal heads, or incorporate a metatarsal bar to decrease the time of metatarsal loading.

We report the management of the acquired claw-toe deformity in ten adults. Each patient developed a varying number of claw toes at a mean interval of six months after the time of injury. There was clinical evidence of an acute compartment syndrome in one case. The clawing occurred at the start of heel-rise in the stance phase of gait. At this stage the patients complained of increasing pain and pressure on the tips of the toes.

The deformities were corrected by lengthening flexor hallucis longus and flexor digitorum longus alone or in combination. The presence of variable intertendinous digitations between the tendons of flexor hallucis longus and flexor digitorum longus means that in some cases release of flexor hallucis longus alone may correct clawing of lesser toes.