The role of medial ligaments and tibialis posterior in stabilising the medial longitudinal foot arch: a cadaveric gait simulator study.

BACKGROUND: Debate exists whether adult acquired flatfoot deformity develops secondary to tibialis posterior (TibPost) tendon insufficiency, failure of the ligamentous structures, or a combination of both. AIM: The aim of this study is to determine the contribution of the different medial ligaments in the development of acquired flatfoot pathology. Also to standardise cadaveric flatfoot models for biomechanical research and orthopaedic training. METHODS: Five cadaveric feet were tested on a dynamic gait simulator. Following tests on the intact foot, the medial ligaments - fascia plantaris (FP), the spring ligament complex (SLC) and interosseous talocalcaneal ligament (ITCL) - were sectioned sequentially. Joint kinematics were analysed for each condition, with and without force applied to TibPost. RESULTS: Eliminating TibPost resulted in higher internal rotation of the calcaneus following the sectioning of FP and SLC (d>1.28, p = 0.08), while sectioning ITCL resulted in higher external rotation without TibPost (d = 1.24, p = 0.07). Sequential ligament sectioning induced increased flattening of Meary's angle. CONCLUSION: Function of TibPost and medial ligaments is not mutually distinctive. The role of ITCL should not be neglected in flatfoot pathology; it is vital to section this ligament to develop flatfoot in cadaveric models.

Transverse laxity of the forefoot.

BACKGROUND: Splay of the forefoot reflects the loss of tension in the soft tissues and indicates failure of the biomechanics of the tie-bar system. By identifying and quantifying the soft tissue structures involved in the destruction of forefoot stability we could increase the understanding of forefoot pathologies. METHODS: We investigated the transverse forefoot laxity on healthy feet, feet with forefoot pathology and cadaveric feet undergoing sequential dissection. RESULTS: Statistical difference in transverse laxity was seen between healthy feet (n = 160) and feet with symptomatic forefoot pathology requiring surgery (n = 29). Presence of lesser ray pathology is associated with increased transverse laxity. For the dissected cadaveric feet (n = 9) sequential sectioning the plantar plate causes a progressive evolution of transverse laxity. The repair of plantar plates greatly improves transverse stability. CONCLUSIONS: Forefoot pathology causes increased transverse laxity. In case of a major transverse laxity of the forefoot a plantar plate lesion should be suspected.

Limited plantar incision for flexor digitorum longus tendon harvest in surgical treatment of tibialis posterior tendon insufficiency.

BACKGROUND: Surgical correction of stage II tibialis posterior tendon dysfunction (TPTD) commonly utilises the Flexor Digitorum Longus (FDL) tendon to augment the tibialis posterior tendon. The aim of this study is to present our experience and clinical outcomes harvesting the FDL via a limited plantar incision technique. METHODS: 25 flat foot operations for stage II TPTD were performed harvesting the FDL via a limited plantar incision centred half-way between the base of the heel to the base of the 2nd toe and two-thirds from the lateral border of the foot. RESULTS: The FDL was isolated with no inter-tendonous connections requiring surgical division. There were no recorded cases of plantar nerve injury nor any technique-related complications observed. CONCLUSIONS: The plantar harvest technique for FDL is safe, provides a long tendon graft for transfer and limits the need for an extensive medial midfoot dissection.

ACL reconstruction combined with lateral monoloop tenodesis can restore intact knee laxity.

PURPOSE: An anterior cruciate ligament (ACL) injury is often combined with injury to the lateral extra-articular structures, which may cause a combined anterior and rotational laxity. It was hypothesised that addition of a 'monoloop' lateral extra-articular tenodesis (mLET) to an ACL reconstruction would restore anteroposterior, internal rotation and pivot-shift laxities better than isolated ACL reconstruction in combined injuries. METHOD: Twelve cadaveric knees were tested, using an optical tracking system to record the kinematics through 0°-100° of knee flexion with no load, anterior and posterior translational forces (90 N), internal and external rotational torques (5 Nm), and a combination of an anterior translational (90 N) plus internal rotational load (5 Nm). They were tested intact, after sectioning the ACL, sectioning anterolateral ligament (ALL), iliotibial band (ITB) graft harvest, releasing deep ITB fibres, hamstrings tendon ACL reconstruction, mLET combined with ACL reconstruction, and isolated mLET. Two-way repeated-measures ANOVA compared laxity data across knee states and flexion angles. When differences were found, paired t tests with Bonferroni correction were performed. RESULTS: In the ACL-deficient knee, cutting the ALL significantly increased anterior laxity only at 20°-30°, and only significantly increased internal rotation at 50°. Additional deep ITB release significantly increased anterior laxity at 40°-90° and caused a large increase of internal rotation at 20°-100°. Isolated ACL reconstruction restored anterior drawer, but significant differences remained in internal rotation at 30°-100°. After adding an mLET there were no remaining differences with anterior translation or internal rotation compared to the intact knee. With the combined injury, isolated mLET allowed abnormal anterior translation and rotation to persist. CONCLUSIONS: Cutting the deep fibres of the ITB caused large increases in tibial internal rotation laxity across the range of knee flexion, while cutting the ALL alone did not. With ACL deficiency combined with anterolateral deficiency, ACL reconstruction alone was insufficient to restore native knee rotational laxity. However, combining a 'monoloop' lateral extra-articular tenodesis with ACL reconstruction did restore native knee laxity.

Treatment of acute spondylolysis in elite athletes. Literature review and presentation of a new percutaneous grafting technique.

The initial treatment of acute spondylolysis in young elite athletes is conservative. Excellent clinical results are seen when there is osseous healing of the defect. When there is no osseous healing, repetitive and maximal loading of the lumbar spine often remain painful. Osseous healing is more likely when lesions are diagnosed and treated early. When no signs of healing are present at computed tomography (CT-scan) after 4 months of conservative treatment and when pain persists, percutaneous surgical treatment can be considered in elite athletes. We present a new percutaneous bone grafting technique for young elite athletes with acute spondylolysis. Osseous healing was achieved and the patient was able to resume competitive sport activities within 6 months after surgery. This technique can improve fracture biology without muscle damage and without affecting the normal mobility of the spine, eventually leading to osseous healing.