The effect of lengthening the gastrocnemius muscle in chronic therapy resistant plantar fasciitis.

BACKGROUND: The aetiology of chronic therapy resistant plantar fasciitis (CTRPF) is multifactorial with more focus in recent times on the gastroc-soleus complex. This study evaluates the effect of lengthening the gastrocnemius muscle in CTRPF. METHODS: All patients with CRTPF complaints for at least one year underwent the same standard conservative treatment prior to surgery. 32 patients failed this treatment and underwent gastrocnemius recession. Silfverskiöld test, questionnaires and plantar pressure measurements were obtained at 5 visits. RESULTS: One year follow up showed a significantly increase in dorsiflexion of the ankle (16 degrees), a decrease in VAS; 78 (SD: 19) to 20 (SD: 24) and significant improved functional scores. Plantar pressure measurements showed an increase of pressure under the medial proximal part of the midfoot and the 1 st metatarsal and a decrease under the hallux. CONCLUSIONS: A gastrocnemius recession results in a significant gain in dorsiflexion, altered loading of the foot and good clinical outcome in patients with CTRPF. LEVEL OF EVIDENCE: Level 2.

PAPPI: Personalized analysis of plantar pressure images using statistical modelling and parametric mapping.

Quantitative analyses of plantar pressure images typically occur at the group level and under the assumption that individuals within each group display homogeneous pressure patterns. When this assumption does not hold, a personalized analysis technique is required. Yet, existing personalized plantar pressure analysis techniques work at the image level, leading to results that can be unintuitive and difficult to interpret. To address these limitations, we introduce PAPPI: the Personalized Analysis of Plantar Pressure Images. PAPPI is built around the statistical modelling of the relationship between plantar pressures in healthy controls and their demographic characteristics. This statistical model then serves as the healthy baseline to which an individual's real plantar pressures are compared using statistical parametric mapping. As a proof-of-concept, we evaluated PAPPI on a cohort of 50 hallux valgus patients. PAPPI showed that plantar pressures from hallux valgus patients did not have a single, homogeneous pattern, but instead, 5 abnormal pressure patterns were observed in sections of this population. When comparing these patterns to foot pain scores (i.e. Foot Function Index, Manchester-Oxford Foot Questionnaire) and radiographic hallux angle measurements, we observed that patients with increased pressure under metatarsal 1 reported less foot pain than other patients in the cohort, while patients with abnormal pressures in the heel showed more severe hallux valgus angles and more foot pain. Also, incidences of pes planus were higher in our hallux valgus cohort compared to the modelled healthy controls. PAPPI helped to clarify recent discrepancies in group-level plantar pressure studies and showed its unique ability to produce quantitative, interpretable, and personalized analyses for plantar pressure images.

Gastrocnemius recession: A cadaveric study of surgical safety and effectiveness.

Background and purpose - Many methods of gastrocnemius lengthening have been described, with different surgical challenges, outcomes, and risks to the sural nerve. Our aims were (1) to locate the gastrocnemius muscular-tendinous junction in relation to the mid-length of the fibula (from here on designated the mid-fibula), (2) to compare the dorsiflexion achieved with dorsal recession or ventral recession, and (3) to determine the risk of injury to the sural nerve during gastrocnemius recession. Methods - In 10 pairs of fresh-frozen adult cadaveric lower extremities transected above the knee, we measured dorsiflexion, performed dorsal or ventral gastrocnemius recession at the mid-fibula, and then measured the increase in dorsiflexion and fasciotomy gap. We noted the course of the sural nerve and whether the gastrocnemius muscle provided it with enough muscular coverage to protect it during recession. Results - Dorsal and ventral recession produced statistically (p < 0.05) and clinically significant mean increases in dorsiflexion with extended knee from 12° to 19°, but they were not statistically significantly different from each other in this measure or in fasciotomy gap size. At the mid-fibula, the sural nerve coursed superficially between both heads of the gastrocnemius muscle in 14 of 20 specimens. Sufficient gastrocnemius muscle coverage to protect the sural nerve was provided by the medial head in 18 of 20 specimens and by the lateral head in only 5 of 20 specimens. Interpretation - A ventral gastrocnemius recession proximal to the mid-fibula level poses less risk to the sural nerve than a recession at the mid-fibula. This procedure provides adequate lengthening (1-3 cm) and increased dorsiflexion (compared with baseline), with less risk to the sural nerve than is incurred with recession at the mid-fibular reference line.

The effect of posture on the osseous relations in the foot.

BACKGROUND: Discrepancies observed between clinical findings and a weightbearing foot X-ray might be caused by a patients' positioning. This study's main objective was to determine the effect of a subjects' posture on the osseous relations of the foot. METHODS: Anatomical markers were placed on the skin of the foot of 17 subjects. A plantar pressure plate assessed the percentage weight on the foot and weight distribution over the foot. Medial longitudinal foot angles were derived from the markers and compared between the 10 postures. The effect of percentage weight and weight distribution on the foot angles was determined by multiple regression analysis. RESULTS: The foot angles were significantly affected by the postures. The multiple regression analysis revealed the weight on the foot and the mediolateral weight distribution over the foot as important factors for the foot angles. CONCLUSION: A subjects posture significantly influences the osseous relations in the foot.

Biomechanical comparison of the interosseous tibiofibular ligament and the anterior tibiofibular ligament.

BACKGROUND: The mechanical importance of the interosseous tibiofibular ligament of the ankle is unclear. The purpose of the current study was to compare the stiffness and strength of the interosseous tibiofibular ligament to that of the anterior tibiofibular ligament. METHODS: Twelve pairs of ankles were obtained from the Maryland State Anatomy Board. All soft tissue was removed except for the interosseous tibiofibular ligament in one ankle of each pair and the anterior tibiofibular ligament in the contralateral ankle. The assignment of which ligament would be excised in the right or left ankle of each pair was random. The specimens were potted as bone-ligament-bone preparations and mounted in a servohydraulic testing machine so that the ligament's long axis was coincident with the actuator. Specimens were elongated at 0.5 mm/s until rupture. Failure load and failure site were recorded, and stiffness was calculated. Stiffness and failure loads were compared with a paired t-test. Significance was set at p < 0.05. RESULTS: The interosseous ligament was significantly stiffer (234 +/- 122 N/mm) than the anterior tibiofibular ligament (162 +/- 64 N/mm). The mean failure load of the interosseous tibiofibular ligament (822 +/- 298 N) was significantly greater than that of the anterior tibiofibular ligament (625 +/- 255 N). CONCLUSIONS: The interosseous tibiofibular ligament is stiffer and stronger than the anterior tibiofibular ligament. CLINICAL RELEVANCE. The current study suggests that the interosseous ligament plays an important role in the stability of the ankle, and its status should be part of the diagnostic evaluation in syndesmotic instability.

Sonography after total hip replacement: reproducibility and normal values in 47 clinically uncomplicated cases.

BACKGROUND AND PURPOSE: Interpretation of sonographic data is difficult when hematoma after total hip replacement is suspected, as there are no normative data. We describe the normal sonographic image, focusing on the amount and location of postoperative fluid collections after a clinically uncomplicated, primary total hip replacement by the posterior approach. Inter- and intraobserver reproducibility is also considered. PATIENTS AND METHODS: We performed sonography of the hip in 47 patients between the second and the fifth postoperative day. Bone-to-capsule distance and deep and superficial extraarticular fluid collections were measured. Intraclass correlation coefficients were calculated. RESULTS: The normal values of bone-to-capsule distance and amount of extraarticular fluid after total hip replacement were established from the upper bound of the 95% confidence interval. The upper bound for bone-capsule distance was 6 mm, for deep fluid collections 21 mm, and for superficial fluid collections 28 mm. In this clinically normal patient group, 4 patients had an extreme value (< 3 SD) for bone-to-capsule distance. For the deep and superficial fluid collections, no extremes were found. No correlation was found between bone-to-capsule distance and whether or not there was extraarticular fluid. Intraclass correlation coefficients were 0.98 for bone-to-capsule distance and 0.99 for fluid collection measurements. INTERPRETATION: Sonography is a reproducible method for the evaluation of fluid collections after total hip replacement. The values measured can be helpful in decision making when there is clinical suspicion of postoperative hematoma after hip replacement by the posterior approach.

Percutaneous Achilles tendon lengthening: a cadaver-based study of failure of the triple hemisection technique.

BACKGROUND AND PURPOSE: Modern descriptions of the percutaneous triple hemisection technique for Achilles tendon lengthening do not take into account the axial twist in the ligament. We were concerned that technical failures of the lengthening technique might occur more often than has been reported, and analyzed the results of the triple hemisection technique in cadaveric tendons in quantitative and qualitative terms, focusing on insufficient or complete tenotomies. METHODS: We performed a percutaneous triple hemisection of the Achilles tendon in 20 legs from adult cadavers, and measured the increase in ankle dorsiflexion in degrees, the length of the cuts in mm, and the depth of the cuts as a percentage of the total diameter of the tendon. Failure of the hemisection was defined as a sliding gap of