Early Achilles Research Articles

Clinical and Imaging Outcomes Over 12 Weeks in Elite Athletes With Early-Stage Tendinopathy.

Knowledge of how to treat chronic tendinopathy has advanced in recent years, but the treatment of early tendinopathy is not well understood. The main purpose of this prospective observational study was to investigate if changes occur in clinical and imaging outcomes over 12 weeks in elite athletes with recent debut of tendinopathy. Sixty-five elite adult athletes (24 ± 5 years) with early Achilles or patellar tendinopathy (symptoms < 3 months) were examined at baseline and after 12 weeks. Patients were divided into groups based on the duration of symptoms at the time of inclusion: (T1): 0-1 month, (T2): 1-2 months, or (T3): 2-3 months. Pain-guided activity modification was the only intervention. We assessed the following clinical outcomes: Questionnaires (Victorian Institute of Sports Assessment (VISA)) and pain scores (0-10 numeric rating scale, NRS), structural outcomes from ultrasonography: Thickness, echogenicity, and Doppler flow, and from magnetic resonance imaging: Cross-sectional area (CSA), thickness and length. Tendinopathic Achilles and patellar tendons displayed no significant differences on imaging tendon structural outcomes between T1 (n = 19), T2 (n = 23), and T3 (n = 20) at baseline or after 12 weeks, with one exception: Patellar tendons in T1 were thicker than T2 and T3 at baseline. Although athletes improved clinically on VISA and most NRS scores after 12 weeks, affected tendons with greater thickness, CSA and Doppler flow than contralateral tendons at baseline remained unchanged after 12 weeks. In conclusion, these data suggest that early tendinopathy in elite athletes can improve clinically after 12 weeks while morphology remains unchanged.

Combined Assessment of 2-D Ultrasound and Real-Time Shear Wave Elastography of Low-Intensity Pulsed Ultrasound Therapy Efficacy in Rabbits with Achilles Tendinopathy

ObjectivesLow-intensity pulsed ultrasound (LIPUS) has been gradually used to treat Achilles tendinopathy. However, there are limited noninvasive and efficient instruments for monitoring the LIPUS efficacy in Achilles tendinopathy. The purpose of this study was to assess the therapeutic effectiveness of LIPUS following Achilles tendinopathy by two-dimensional (2D) ultrasound and real-time shear wave elastography (SWE). MethodsNinety New Zealand white rabbits were divided into control, sham, and LIPUS groups after tendinopathy modeling. On days 1, 4, 7, 14, and 28, the Achilles tendon thickness and SWE Young's modulus on the long axis were measured. The tissues of the Achilles tendon were then evaluated histologically. ResultsThe mean SWE values increased while the average thickness and histologic scores decreased, especially in the LIPUS group (9.5% and 80.7% on Day 28, respectively). The SWE values in the LIPUS group were significantly lower than those in the control group on Day 1 (121.0 KPa vs. 177.6 KPa) and peaked on Day 7 (173.7 KPa, p<0.001). By Day 28, the SWE value had approached that of the control (191.2 KPa vs. 192.4 KPa), and it had been significantly higher than that in the sham group since Day 7. SWE values and histologic scores were correlated (r = -0.792, p<0.01). The average thickness decreased in the three groups but did not show significant differences. Conclusions2D ultrasound is beneficial to the diagnosis of Achilles tendinopathy. SWE could quantify changes in Achilles tendon stiffness noninvasively during LIPUS treatment, enabling the study of early Achilles tendon healing after LIPUS treatment.

Conservative Treatment Outcomes for Achilles Tendon Re-Rupture Occurring in the Subacute Phase after Primary Repair

Category: Ankle; Sports Introduction/Purpose: Achilles tendon re-rupture (ATRR) during the subacute postoperative phase is the rupture of the repaired site combined with suture material failure induced by an unexpected traumatic event during postoperative months one to three after primary Achilles tendon repair. This study aimed to determine the effectiveness of conservative treatment for subacute ATRR. Methods: We retrospectively reviewed 390 cases (385 patients) who underwent primary Achilles tendon repair between January 2010 and August 2021. All patients had more than 12 months of follow-up and were divided into two groups based on the development of subacute ATRR (Group 1: 370 cases without ATRR; Group 2: 20 cases with ATRR). Then, we compared several outcome parameters between the groups after administering conservative treatment to those with ATRR. The baseline timepoints in Groups 1 and 2 were the primary repair and re-injury dates. Results: After primary Achilles tendon repair, 5.13% of patients experienced subacute ATRR. The time to performing a single heel raise (SHR) and performing ten repetitive SHRs did not differ between the groups (P = 0.281, 0.486). Likewise, isokinetic dynamometer results showed that the peak torque of 30o/s and 120o/s plantar flexions (the absolute value and the percentage to the contralateral side) also did not differ between the groups (P &gt;0.05, each). However, the early Achilles tendon Total Rupture Score scale and the Foot and Ankle Ability Measure scores before six months were significantly lower in Group 2 than in Group 1 (both P &lt; 0.05); at 12 months, the scores did not differ between the two groups (both P &gt;0.05). Conclusion: Conservative treatment for subacute ATRR after primary Achilles tendon repair has comparable clinical outcomes to those without ATRR.

Achilles tenotomy during Ponseti's clubfoot treatment: better early than late.

To evaluate the outcome of Achilles tenotomy at first cast in neonates with stiff clubfoot undergoing Ponseti's method of treatment. One hundred forty stiff clubfeet (Dimeglio grades III and IV) scheduled for Ponseti's method were prospectively randomized into two groups of 70 each: (1) early, tenotomy at first cast; (2) late, tenotomy at fourth to sixth casts (conventional). The procedure was performed under local lidocaine spray in an office setting using a needle. The results were assessed at an average follow-up of 12.4 years. Technical difficulties and short and long-term complications were recorded. At last follow-up, the results were rated excellent, good, fair, and poor in 70, 18, 9, and 3% of patients in the late group, respectively, and 82, 13, 4, and 1% in the early group ( P = 0.048). Technical difficulties were encountered in 38% of the late group and 3% in the early group ( P < 0.0001). Flattening of the talar dome of mild to moderate severity was found in 16% of the late group and 4% in the early group ( P < 0.001). Early Achilles tenotomy seems to give better results than the conventional late tenotomy, with less short and long-term complications. This may be explained by the greater ease to palpate the Achilles tendon on a previously untreated foot, and the less amount of compressive forces across the tibiotalar and subtalar joints produced by early release of the posterior tether.

Assessment of early Achilles tenotomy in the newborn idiopathic pes equinovarus.

We aimed to evaluate the clinical and radiological results of early Achilles tenotomy which was performed before Ponseti method in PEV deformities. 37 feet of 26 patients with Dimeglio type 3 and 4 deformities were included in the study. Unlike the classical Ponseti method, patients underwent a mini-open Achilles tenotomy before the first cast. 6-month follow-up of the foot deformities were assessed using Dimeglio classification clinically and lateral talocalcaneal and tibiocalcaneal angles radiologically. There were 20 male and 6 female patients with the median age of 14 days (4-37 days) and 11 bilateral and 15 unilateral deformities. The average follow-up period was 7 months (6-12 months). The mean Dimeglio scores before the Achilles tenotomy and Dimeglio score at the 6 th month follow-up were 14 (11-16) and 4 (4-6) for the right feet, 13 (10-16) and 4 (4-6) for the left feet respectively. The mean number of casting was 3.8 ± 0.4 for right feet and 3.7 ± 0.4 for left feet. The mean talocalcaneal angle was 24 ± 8.2 degrees for the right feet and 27 ± 8.2 degrees for the left feet. The mean tibiocalcaneal angle was 69 ± 12 for the right feet and 72 ± 14 degrees for the left feet. Early Achilles tenotomy can decrease the total number of cast for deformity correction in Ponseti method and provide good clinical and radiological outcomes at 6 th month follow-up in severe PEV deformities according to Dimeglio classification.

Role of Macrophages During early Achilles Tendon Healing

Role of Macrophages During early Achilles Tendon Healing

T1 and T2 Mappings in the Early Diagnosis of Achilles Tendinosis

Objective: The purpose of this study was to compare T1 and T2 relaxation times of normal and pathologic Achilles Tendon (AT) in order to evaluate the ability of these methods to detect early Achilles tendon tendinosis. Materials and Methods: Forty-eight subjects were included in this study. Twenty-two subjects were classified as normal group and twenty-six subjects as patient group with tendinosis. MR examination was performed by 3 Tesla scanner using a 12 channel head coil. For relaxation times quantification, we used a sagittal 3D FLASH variable flip angle gradient echo UTE sequence (3D VFA-GE UTE) for T1 mapping and a sagittal Multi Echo Spin Echo sequence (MESE) for T2 mapping. Relaxation times were quantified using two different algorithms written in MATLAB. P value &lt; 0.05 was considered statistically significant. Results: Our results showed a statistically significant difference in T1 and T2 values for the normal group compared to the patient group (p&lt;0.05). Mean values of T1 and T2 were 571.69 ms and 24.16 ms for the normal group and 818.10 ms and 32.43 ms for the patient group, respectively. Results reported no correlation (r=0.193) for T1 mapping and a positive significant moderate correlation (r=0.542, p=0.000) for T2 mapping between the normal and patient groups. T1 and T2 showed no correlation in the normal group (r= 0.091, p=0.489) and a positive significant weak correlation in the patient group (r=0.263, p=0.048). Conclusion: We concluded that T1 and T2 relaxation times are relatively sensitive to diagnosis degenerative changes in the AT and T1 is more sensitive to AT tendinosis compared to T2.

Early Achilles Enthesis Involvement in a Murine Model of Spondyloarthropathy: Morphological Imaging with Ultrashort Echo-Time Sequences and Ultrasmall Superparamagnetic Iron Oxide (USPIO) Particle Evaluation in Macrophagic Detection.

Purpose To confirm the interest of 3-dimensional ultrashort echo-time (3D-UTE) sequences to assess morphologic aspects in normal and pathological Achilles entheses in a rat model of spondyloarthropathy (SpA) with histological correlations, in comparison with conventional RARE T2 Fat-Sat sequences, and, furthermore, to evaluate the feasibility of a 3D multiecho UTE sequence performed before and after the intravenous injection of ultrasmall superparamagnetic iron oxide (USPIO) particles to assess macrophagic involvement in the Achilles enthesis in the same rat model of SpA. Materials and Methods Fourteen rats underwent in vivo MRI of the ankle at 4.7 T, including a 3D RARE T2 Fat-Sat sequence and a 3D ultrashort echo-time (UTE) sequence for morphologic assessment at baseline and day 3 after induction of an SpA model, leading to Achilles enthesopathy in the left paw (right paw serving as a control). A 3D multiecho UTE sequence was also performed at day 3 before and then 24 (4 rats) and 48 (2 rats) hours after intravenous injection of USPIO. Visual analysis and signal intensity measurements of all images were performed at different locations of the Achilles enthesis and preinsertional area. Visual analysis and T2∗ measurements were performed before and after USPIO injection, on the 3D multiecho UTE sequence in the same locations. Normal and pathological values were compared by Wilcoxon signed-rank tests. MR findings were compared against histological data. Results 3D-UTE sequences enabled morphologic identification of the anterior fibrocartilage and posterior collagenic areas of the Achilles enthesis. Visual analysis and signal intensity measurements distinguished SpA-affected entheses from healthy ones at day 3 (P=0.02). After administration of USPIO, no differences in signals were detected. Similarly, both visual analysis and signal T2∗ measurements in the enthesis were unable to distinguish the SpA-affected tendons from healthy ones (P=0.914). Neither the normal anatomy of the enthesis nor its pathological pattern could be distinguished using the standard RARE sequence. Histology confirmed the absence of USPIO in Achilles entheses, despite marked signs of inflammation. Conclusion Unlike conventional RARE T2 Fat-Sat sequences, 3D-UTE sequences enable morphologic assessment of normal enthesis anatomy and early detection of abnormalities in pathological conditions. However, 3D multiecho UTE sequences combined with USPIO injections with T2∗ measurements were unable to detect macrophagic involvement in these pathological conditions.

Extracellular Vesicle-Educated Macrophages Promote Early Achilles Tendon Healing.

Tendon healing follows a complex series of coordinated events, which ultimately produces a mechanically inferior tissue more scar‐like than native tendon. More regenerative healing occurs when anti‐inflammatory M2 macrophages play a more dominant role. Mesenchymal stromal/stem cells (MSCs) are able to polarize macrophages to an M2 immunophenotype via paracrine mechanisms. We previously reported that coculture of CD14+ macrophages (MQs) with MSCs resulted in a unique M2‐like macrophage. More recently, we generated M2‐like macrophages using only extracellular vesicles (EVs) isolated from MSCs creating “EV‐educated macrophages” (also called exosome‐educated macrophages [EEMs]), thereby foregoing direct use of MSCs. For the current study, we hypothesized that cell therapy with EEMs would improve in vivo tendon healing by modulating tissue inflammation and endogenous macrophage immunophenotypes. We evaluated effects of EEMs using a mouse Achilles tendon rupture model and compared results to normal tendon healing (without any biologic intervention), MSCs, MQs, or EVs. We found that exogenous administration of EEMs directly into the wound promoted a healing response that was significantly more functional and more regenerative. Injured tendons treated with exogenous EEMs exhibited (a) improved mechanical properties, (b) reduced inflammation, and (c) earlier angiogenesis. Treatment with MSC‐derived EVs alone were less effective functionally but stimulated a biological response as evidenced by an increased number of endothelial cells and decreased M1/M2 ratio. Because of their regenerative and immunomodulatory effects, EEM treament could provide a novel strategy to promote wound healing in this and various other musculoskeletal injuries or pathologies where inflammation and inadequate healing is problematic. Stem Cells 2019;37:652–662

Adipose-derived Human Perivascular Stem Cells May Improve Achilles Tendon Healing in Rats.

Achilles tendon rupture is a common injury and the best treatment option remains uncertain between surgical and nonoperative methods. Biologic approaches using multipotent stem cells such as perivascular stem cells pose a possible treatment option, although there is currently a paucity of evidence regarding their clinical therapeutic use. The purpose of this study was to determine whether injected perivascular stem cells (PSCs) would (1) improve histologic signs of tendon healing (such as percent area of collagen); and (2) improve biomechanical properties (peak load or stiffness) in a rat model of Achilles tendon transection. Two subtypes of PSCs were derived from human adipose tissue: pericytes (CD146CD34CD45CD31) and adventitial cells (CD146CD34CD45CD31). Thirty-two athymic rats underwent right Achilles transection and were randomized to receive injection with saline (eight tendons), hydrogel (four tendons), pericytes in hydrogel (four tendons), or adventitial cells in hydrogel (eight tendons) 3 days postoperatively with the left serving as an uninjured control. Additionally, a subset of pericytes was labeled with CM-diI to track cell viability and localization. At 3 weeks, the rats were euthanized, and investigators blinded to treatment group allocation evaluated tendon healing by peak load and stiffness using biomechanical testing and percent area of collagen using histologic analysis with picrosirius red staining. Histologic analysis showed a higher mean percent area collagen for pericytes (30%) and adventitial cells (28%) than hydrogel (21%) or saline (26%). However, a nonparametric statistical analysis yielded no statistical difference. Mechanical testing demonstrated that the pericyte group had a higher peak load than the saline group (41 ± 7 N versus 26 ± 9 N; mean difference 15 N; 95% confidence interval [CI], 4-27 N; p = 0.003) and a higher peak load than the hydrogel group (41 ± 7 N versus 25 ± 3 N; mean difference 16; 95% CI, 8-24 N; p = 0.001). The pericyte group demonstrated higher stiffness than the hydrogel group (36 ± 12 N/mm versus 17 ± 6 N/mm; mean difference 19 N/mm; 95% CI, 5-34 N/mm; p = 0.005). Our results suggest that injection of PSCs improves mechanical but not the histologic properties of early Achilles tendon healing. This is a preliminary study that provides more insight into the use of adipose-derived PSCs as a percutaneous therapy in the setting of Achilles tendon rupture. Further experiments to characterize the function of these cells may serve as a pathway to development of minimally invasive intervention aimed at improving nonoperative management while avoiding the complications associated with surgical treatment down the line.

Therapeutic potential of hAECs for early Achilles tendon defect repair through regeneration.

Cell-based therapy holds great promise for tendon disorders, a widespread debilitating musculoskeletal condition. Even if the cell line remains to be defined, preliminary evidences have proven that amniotic-derived cells possess in vitro and in vivo a great tenogenic potential. This study investigated the efficacy of transplanted human amniotic epithelial cells (hAECs) by testing their early regenerative properties and mechanisms involved on a validated ovine Achilles tendon partial defect performed on 29 animals. The injured tendons treated with hAECs recovered rapidly, in 28days, structural and biomechanical properties undertaking a programmed tissue regeneration, differently from the spontaneous healing tissues. hAECs remained viable within the host tendons establishing with the endogenous progenitor cells an active dialogue. Through the secretion of modulatory factors, hAECs inhibited the inflammatory cells infiltration, activated the M2 macrophage subpopulation early recruitment, and accelerated blood vessel as well as extracellular matrix remodelling. In parallel, some in situ differentiated hAECs displayed a tenocytelike phenotype. Both paracrine and direct hAECs stimulatory effects were confirmed analysing their genome profile before and after transplantation. The 49 human up-regulated transcripts recorded in transplanted hAECs belonged to tendon lineage differentiation (epithelial-mesenchymal transition, connective specific matrix components, and skeleton or muscle system development-related transcripts), as well as the in situ activation of paracrine signalling involved in inflammatory and immunomodulatory response. Altogether, these evidences support the hypothesis that hAECs are a practicable and efficient strategy for the acute treatment of tendinopathy, reinforcing the idea of a concrete use of amniotic epithelial cells towards the clinical practice.

Y a-t-il vraiment une différence concernant le timing de la ténotomie d’Achille au cours du traitement du pied bot varus équin par la méthode de Ponseti ?

Introduction Ponseti method for congenital idiopathic clubfoot correction has traditionally included a percutaneous Achilles tenotomy in more than 90% of stiff cases. The latter is usually performed during the fourth to sixth cast application and has proven to be the key factor for success of nonoperative treatment. However, in some cases it may not be easy to palpate the tendon and perform the procedure percutaneously owing to the swelling produced by repeated casting and a mini-incision may be required. The purpose of this paper was to evaluate the influence of early Achilles tenotomy during management of clubfoot using Ponseti method in neonates with Dimeglio types III and IV deformities. Methods Ninety neonates with 140 stiff clubfeet, according to Dimeglio, scheduled to undergo Ponseti method were prospectively randomly assigned into 2 groups - 70 feet underwent the percutaneous tenotomy during the first casting session (early group EG) and 70 during the 6th casting session (late group LG). Procedure is performed in an outpatient clinic setting without any anesthesia other than local skin application of lidocaine spray. Achilles tendon is palpated and an 18-gauge needle is introduced through the skin along its medial border few millimeters above its distal insertion on the calcaneus. Tendon is cut from medial to lateral in 1–3 needle swipes while foot is held in forced dorsiflexion. Cast is then applied according to Ponseti. Patients were reviewed at an average follow-up of 7.4 years (5.2–10.8) and results were assessed using Ghanem-Seringe score. Technical difficulties, postoperative blood staining on cast and short- and long-term complications were recorded. Results Results were rated excellent, good, fair, and poor in 70%, 18%, 9% and 3% of patients respectively in LG and 82%, 13%, 4% and 1% of patients, respectively in EG ( P = 0.05). Flattening of the talar dome of mild to moderate severity was found in 16% in LG and 4% of EG ( P P P Discussion Percutaneous Achilles tendon performed as early as during first casting session seems to give greater excellent results than when performed during 6th casting session as described by Ponseti, with less short- and long-term complications. This may be explained by greater ease to palpate Achilles tendon and perform a clear-cut and selective tenotomy on a virgin foot, and early decrease in compressive forces over talar dome during corrective maneuvers.

Application of internal fixation of steel–wire limited loop in early Achilles tendon rupture

ObjectiveTo explore the clinical effect and safety of internal fixation of steel–wire limited loop in early Achilles tendon rupture. MethodsSeventy–six patients respectively with early transected and avulsed types of Achilles tendon rupture were selected and treated with internal fixation of steel–wire limited loop. The patients began to take exercise for their lower limbs through continous passive motion as early as possible after surgical repair, and the loops were removed after 3–5 months. Six months later, the condition of complications including Achilles tendon re–rupture, wound fistula, wound infection and skin necrosis, cutaneous sensation in sural nerve dominance region, time back to preinjury work or learning as well as time to physical activities were observed. One year later, the therapeutic effect was evaluated, and the maximum circumferences of bilateral legs and ruptured plane circumferences of Achilles tendon were measured. ResultsThe wound of all patients healed well, no complications like Achilles tendon re–rupture, wound fistula, wound infection and skin necrosis occured, and the cutaneous sensation in sural nerve dominance region was normal. The mean time back to preinjury work or learning as well as to pysical activities of all patients were respectively 10 and 22 weeks. Seventy out of 76 patients (92.1%) achieved an excellent effect, and 6 (7.9%) good effect. The excellent and good rate came up to 100%. The maximum circumference in the affected leg decreased to 2 mm averagely compared with the offside, while the ruptured plane circumferences of Achilles tendon in the affected side increased to 2.2 mm compared with the offside. ConclusionsFor early Achilles tendon rupture, internal fixation of steel–wire limited loop can recover the ankle function better, return to the preinjury state in the shortest time, and has few complications.

Metabolic activity in early tendon repair can be enhanced by intermittent pneumatic compression

Since Achilles tendon healing is protracted, more knowledge of metabolites known to meet the demands for biosynthesis and proliferation is needed. We hypothesized that essential metabolites, glutamate, glucose, lactate, pyruvate and glycerol, are present and upregulated in healing Achilles tendons. We moreover hypothesized that adjuvant intermittent pneumatic compression (IPC), which increases blood flow, upregulates metabolite concentrations. Twenty patients with acute Achilles tendon rupture were recruited, operated, and included. The control group, 15 patients, received plaster cast immobilization, while five patients received adjuvant foot IPC beneath the plaster cast. At 2 weeks postoperatively, microdialysis of the healing and contralateral intact Achilles tendons was followed by quantification of metabolites. Healing compared to intact tendons of the controls exhibited significantly increased concentrations (mM) of glutamate (60 ± 14 vs 20 ± 11), lactate (1.15 ± 0.60 vs 0.64 ± 0.35), and pyruvate (81 ± 29 vs 35 ± 25, μM). Healing tendons of the IPC vs control group displayed higher levels of glutamate (84 ± 15 vs 62 ± 16) and glucose (3.44 ± 0.62 vs 2.62 ± 0.72); (P < 0.05) and trends toward higher concentrations of pyruvate, lactate, and glycerol (P < 0.10). The present study demonstrates that early Achilles tendon repair entails and upregulates local essential metabolites. This metabolic response can, during tendon healing with plaster cast immobilization, be promoted by adjuvant IPC.

Second harmonic generation analysis of early Achilles tendinosis in response to in vivo mechanical loading

BackgroundTenocytes have been implicated in the development of tendinosis, a chronic condition commonly seen in musculoskeletal overuse syndromes. However, the relation between abnormal tenocyte morphology and early changes in the fibrillar collagen matrix has not been closely examined in vivo. Second harmonic generation (SHG) microscopy is a recently developed technique which allows examination of fibrillar collagen structures with a high degree of specificity and resolution. The goal of this study was to examine the potential utility of SHG and multiphoton excitation fluorescence (MPEF) microscopy in understanding the relation between tenocytes and their surrounding collagenous matrix in early tendon overuse lesions.MethodsHistological preparations of tendon were prepared from adult male Sprague-Dawley rats subjected to an Achilles tendon loading protocol for 12 weeks (Rat-A-PED), or from sedentary age-matched cage controls. Second harmonic generation and multiphoton excitation fluorescence were performed simultaneously on these tissue sections in at least three different areas.ResultsSHG microscopy revealed an association between abnormal tenocyte morphology and morphological changes in the fibrillar collagen matrix of mechanically loaded Achilles tendons. Collagen density and organization was significantly reduced in focal micro-regions of mechanically loaded tendons. These pathological changes occurred specifically in association with altered tenocyte morphology. Normal tendons displayed a regular distribution of fibre bundles, and the average size of these bundles as determined by Gaussian analysis was 0.47 μm ± 0.02. In comparison, fibre bundle measures from tendon regions in the vicinity of abnormal tenocytes could not be quantified due to a reduction in their regularity of distribution and orientation.ConclusionsSHG microscopy allowed high resolution detection of focal tendon abnormalities affecting the fibrillar collagen matrix. With ongoing repetitive loading, these tenocyte-associated focal collagen defects could predispose to the progression of overuse pathology.

The Drop Toe Sign: An Indicator of Neurologic Impairment in Congenital Clubfoot

Nine patients presenting during infancy were identified with clubfeet and absent anterior and lateral compartment functions. We considered these to be neurogenic clubfeet. All patients had the drop toe sign: resting posture of the toes in plantarflexion and absent active dorsiflexion movement after plantar stimulation of the foot. Two patients (three feet) underwent exploration of the peroneal nerve, which revealed anatomic abnormalities. Six patients required more casts than typical for initial correction of deformity; all but two had Achilles tenotomy. Four relapsed despite full-time bracing and eventually needed intraarticular surgery to achieve a plantigrade foot. Idiopathic absent peroneal nerve function is not a well-described entity in the clubfoot literature. All babies with clubfoot should be examined for the drop toe sign. When noted, the feet will likely be more difficult to correct initially, may need early Achilles tendon lengthening, will likely need permanent bracing, are likely to relapse and need intraarticular surgery, and may need multiple surgeries to remain plantigrade throughout growth. Level IV, diagnostic study. See the Guidelines for Authors for a complete description of levels of evidence.

Early Achilles tendon healing in sheep

The biomechanics of early tendon healing is important for designing post-injury training, but this has not been described in an animal model, similar to humans in size. We measured elastic and viscoelastic properties of a tendon regenerate in sheep, in a study designed to see the effects of exogenously applying the growth and differentiation factor CDMP-2. This is the first description of early tendon healing in sheep Achilles tendons. Twenty female sheep underwent Achilles tendon transection without suturing or immobilization. Two hours after the operation, 100 mug of CDMP-2 or placebo was injected into the hematoma. The sheep were slaughtered after 3 weeks, and tendon regenerates tested for viscoelastic properties by cyclical loading, before a destructive tensile test. Thereafter, all specimens were examined by high resolution computerized tomography (CT), and histology. The tendon regenerate formed a sleeve, around the tendon stumps. Failure occurred between the regenerate sleeve and the tendon stumps. There was an unexpectedly large variation in force at failure. In the CDMP-2 group, force correlated with regenerate transverse area, but not in the controls. Thus, the variation in maximum stress was smaller in the CDMP-2 group (P = 0.009). Although the force at failure was only a tenth of normal, the capacity to store elastic energy was already near normal (hysteresis 16%). The mean transverse area, force at failure and stiffness were all about 30% larger in the CDMP-2 group, but this was not significant. There were no signs of bone or cartilage formation on CT or histology. Results are compatible with a positive effect of CDMP-2, but the power was too low to demonstrate any such effect. Considering that spontaneous ruptures in humans are likely to have a more variable geometry than in this model, humans can also be expected to vary a lot in early mechanical characteristics. This emphasizes the importance of individualized rehabilitation programs. The low hysteresis suggests that the energy storing capacity is rather easy for the tissues to develop; possibly it is harder to create appropriate energy dissipation, in order to avoid re-rupture.

The incidence and treatment of rocker bottom deformity as a complication of the conservative treatment of idiopathic congenital clubfoot

Rocker bottom deformity may occur during the conservative treatment of idiopathic congenital clubfoot. Between 1975 and 1996, we treated 715 patients (1120 clubfeet) conservatively. A total of 23 patients (36 feet; 3.2%) developed a rocker bottom deformity. It is these patients that we have studied. The pathoanatomy of the rocker bottom deformity is characterised by a plantar convexity appearing between three and six months of age with the hindfoot equinus position remaining constant. The convexity initially involves the medial column, radiologically identified by the talo-first metatarsal angle and secondly by the lateral column, revealed radiologically as the calcaneo-fifth metatarsal angle. The apex of the deformity is usually at the midtrasal with a dorsal calcaneocuboid subluxation. Ideal management of clubfoot deformity should avoid this complication, with adequate manipulation and splinting and early Achilles' percutaneous tenotomy if plantar convexity occurs. Adequate soft-tissue release provides satisfactory correction for rocker bottom deformity. However, this deformity requires more extensive and complex procedures than the standard surgical treatment of clubfoot. The need for lateral radiographs to ensure that the rocker bottom deformity is recognised early, is demonstrated.