[Treatment of syndesmosis diastasis with screw fixation in ankle fractures].

OBJECTIVE: To explore the operative method for the treatment of syndesmosis injury in ankle fractures. METHODS: A retrospective study was done on 21 ankles of 20 patients included male 11 and female 9;the range of age were from 27 to 52 years with an average of 36 years) with syndesmosis injury in closed ankle fractures from September 2005 to December 2007. All patients with ankle fractures and syndesmosis injury were diagnosed by the history, physical examination and radiology, then treated with open reduction, internal fixation, and syndesmotic stabilization with a three-cortices syndesmotic screw according to the Lauge-Hansen classification system. Radiological evaluation comprised tibiofibular overlap, total clear space and medial clear space. The clinical effects were evaluated according to modified Baird-Jackson standard. RESULTS: All patients were followed up from 1.0 to 2.2 years with an average of 1.3 years. Radiographic measurements were detailed as follows: tibiofibular overlap averaged (0.46 +/- 3.56) mm in preoperative and (7.14 +/- 0.62) mm in postoperative; mean total clear space (5.69 +/-0.88) mm in preoperative and (3.28 +/- 0.39) mm in postoperative; medial clear space averaged (5.67 +/- 1.23) mm in preoperative and (3.12 +/- 0.33) mm in postoperative; tibiofibular overlap in mortise view averaged (-0.87 +/- 0.96) mm in preoperative and (2.91 +/- 0.30) mm in postoperative. There was significant difference above data between preoperative and postoperative (P < 0.01). Four cases were confirmed minor tibiofibular diastasis through CT scans during postoperative. The modified Baird-Jackson scoring was from 62 to 98 scores with an average of (86.24 +/- 13.26) score at the final review. Of them, 13 ankles had not pain; 16 ankles reported no instability complaints; 11 ankles gained normal walking ability; 8 ankles could run normally; 11 ankles could return work without any restrictions. Activity of ankle in dorsiflexion, plantar flexion, inversion and eversion were respectively (21.05 +/- 5.00) degrees, (33.57 +/- 5.76) degrees, (19.48 +/- 4.57) degrees and (24.05 +/- 4.86) degrees. Three cases had radiological and clinical manifestations of osteoarthritis, but no breakage of syndesmotic screw in all cases. There were excellent results in 12 cases, good in 2, fair in 4, poor in 3. CONCLUSION: The treatment for the syndesmosis diastasis with a three-cortices screw fixation in ankle fractures is effective. Good functional outcome can be obtained with anatomical restoration of the tibiofibular syndesmosis. The repair of deltoid ligament is important for stability of the lower tibiofibular syndesmosis. Removal of the screw before weight loading should be performed to avoid possible screw breakage.

Mechanics of tarsal disintegration and plantar ulcers in leprosy by stress analysis in three dimensional foot models.

This paper describes three dimensional two arch models of feet of a normal subject and two leprosy subjects, one in the early stage and the other in the advanced stage of tarsal disintegration, used for analysis of skeletal and plantar soft tissue stresses by finite element technique using NISA software package. The model considered the foot geometry (obtained from X-rays), foot bone, cartilages, ligaments, important muscle forces and sole soft tissue. The stress analysis is carried out for the foot models simulating quasi-static walking phases of heel-strike, mid-stance and push-off. The analysis of the normal foot model shows that highest stresses occur at push-off over the dorsal central part of lateral and medial metatarsals and dorsal junction of calcaneus and cuboid and neck of talus. The skeletal stresses, in early state leprosy with muscle paralysis and in the advanced stage of tarsal distintegration (TD), are higher than those for the normal foot model, by 24% to 65% and 30% to 400%, respectively. The vertical stresses in the soft tissue at the foot-ground interface match well with experimentally measured foot pressures and for the normal and leprosy subjects they are the highest in the push-off phase. In the leprosy subject with advanced TD, the highest soft tissue stresses and shear stresses (about three times the normal value) occur in push-off phase in the scar tissue region. The difference in shear stresses between the sole and the adjacent soft tissue layer in the scar tissue for the same subject is about three times the normal value. It is concluded that the high bone stresses in leprosy may be responsible for tarsal distintegration when the bone mechanical strength decreases due to osteoporosis and the combined effect of high value of footsole vertical stresses, shear stresses and the relative shear stresses between two adjacent soft tissue layers may be responsible for plantar ulcers in the neuropathic leprosy feet.

Tarsal disintegration (T.D.) in leprosy.

Tarsal Disintegration in leprosy has been a challenge as far as its prevention is concerned. It is, no doubt, a complex and less understood phenomenon influenced by many factors. In this study made at Dr. Bandorawalla Leprosy Hospital, Kondhawa, factors like insensitivity, loss of protective reflex, infection, lepromatous infiltration of bones etc. have been taken into consideration, but, more emphasis is laid on the biomechanical factors (i.e. altered muscle pulls due to muscular paralysis resulting in imbalance) and the resulting change in weight bearing areas and weight transmission lines. Sixteen cases of neuropathic feet were examined clinically and radiologically. All were burnt out cases of tuberculoid and borderline tuberculoid variety excepting one which was active being of lepromatous variety. Tracings made from actual radiographs of the patients were studied. It was found that apart from insensitivity, biomechanical factors play a lot of importance in accentuating the process of T.D. The changes are predominantly seen in Tuberculoid variety of Leprosy. Attempts have been made to understand this process more closely by drawing conclusions based on the kinetic and kinematic analysis of the normal human foot and comparing it with neuropathic feet.