Surgical anatomy and accuracy of percutaneous achilles tendon lengthening

Minimally invasive ultrasound-assisted cutting thread tenotomy of the deep digital flexor tendon in horses: An ex vivo study

OBJECTIVE

To evaluate the feasibility and limitations associated with a minimally invasive ultrasound-assisted cutting thread technique for tenotomy of the deep digital flexor tendon (DDFT) in horses.

STUDY DESIGN

Ex vivo study.

SAMPLE POPULATION

Twenty cadaveric forelimbs.

METHODS

Forelimbs were placed on a jig to mimic a standing semiflexed position and the midmetacarpal region was prepared to perform tenotomy of the DDFT using a percutaneous technique with a cutting thread. For that purpose, the thread was placed percutaneously around the DDFT (first dorsally and then palmarly) with the aid of a curved 20 gauge spinal needle. Tendon palpation/manipulation and ultrasonographic assessment assisted thread placement. Procedure time and skin puncture size were recorded. Limbs were then dissected to evaluate the degree of DDFT transection and the presence of any iatrogenic lesions.

RESULTS

The DDFT was completely transected in all cases. Minor lesions of the superficial digital flexor tendon were found in 11/20 limbs and considered clinically irrelevant. However, the neurovascular bundle was damaged in 6/20 limbs (four limbs had nerve damage and two limbs had a nerve and either a palmar artery or vein damaged). The skin puncture hole sizes ranged from undetectable to 5 mm long. The average duration of the procedure was 7 min and 38 s (range: 4 min 56 s to 10 min 19 s).

CONCLUSION

A DDFT tenotomy can be performed reliably with a percutaneous cutting thread technique. However, refinement of the technique is required to minimize iatrogenic damage.

CLINICAL SIGNIFICANCE

The reported technique allows a DDFT tenotomy to be performed in a minimally invasive manner and has the potential to be clinically applicable.

Histopathological assessment of a two-stage reconstructive procedure of the infected Charcot foot

INTRODUCTION

Charcot neuropathic osteoarthropathy (CN) can be complicated by osteomyelitis (OM). Surgery is a standard procedure to treat OM including debridement and interposition of antibiotic-loaded cement (ABLC) spacer. The course of CN and OM was investigated on a histopathological level.

MATERIALS AND METHODS

Diabetic patients (n = 15) suffering from CN and midfoot OM underwent surgical debridement and interposition of ABLC was interposed. 6 weeks later, ABLC was removed and bone samples were taken again. Histopathological Charcot Score (HCS), Histopathological Osteomyelitis Evaluation Score (HOES) and microbiological assessment were used to evaluate osteomyelitic and neuroosteoarthropathic activity at both time points.

RESULTS

Interposition of ABLC leads to microbiological/histopathological eradication of OM in 73%/87% of patients. CN activity-measured by HCS-could be reduced from moderate to low activity by ABLC spacer and correlated with HOES.

CONCLUSIONS

CN activity could be reduced by surgery. It can be suggested that neuroosteoarthropathic activity measured by HCS is triggered by OM.

Effect of single and double hemitenotomy on equine deep digital flexor tendon length and strength in experimental load challenges

OBJECTIVE

To evaluate a double hemitenotomy (DHT) technique as an alternative to complete deep digital flexor (DDFT) tenotomy.

STUDY DESIGN

Experimental ex vivo study.

SAMPLE POPULATION

Isolated DDFTs (n = 30) and cadaveric forelimbs (n = 16).

METHODS

In part 1, 15 isolated DDFT pairs were used. Two hemitenotomies were created in 1 DDFT while the other served as reference. Monotonic tensile load was applied. Tendon lengthening, load reduction, and load at failure were recorded. In part 2, 16 cadaveric forelimb pairs were subjected to DHT followed by complete tenotomy (CT) under monotonic compressive load. Differences between DHT and controls were assessed with Wilcoxon signed rank tests or Friedman tests.

RESULTS

In isolated tendons and cadaveric forelimbs, DHT resulted in DDFT lengthening (median, +1.9 mm and + 3.05 mm) and load reduction (median, -16.7 and -11.2 kg). Less lengthening was achieved with DHT compared to CT (P = .008). Load reduction did not occur between DHT and CT was observed during compressive testing (P = 1). Load reduction following the first hemitenotomy incision was smaller when compared to the second (P = .022). Isolated DHT tendons failed at a tensile load of 195 kg, while no intact tendons failed (P = .0001).

CONCLUSION

Double hemitenotomy was comparable to CT in load reduction. It reduced tensile strength, but load at failure was similar or exceeded the estimated DDFT load at stance.

CLINICAL SIGNIFICANCE

Hemitenotomy may be a useful alternative for surgical management of horses with laminitis, but in vivo studies are needed to confirm these findings.

Relation of the Sural Nerve and Medial Neurovascular Bundle With the Achilles Tendon in Children With Cerebral Palsy Treated by Percutaneous Achilles Tendon Lengthening

BACKGROUND

One of the most common treatment options for a short Achilles tendon (AT) in cerebral palsy is percutaneous AT lengthening using 3 hemisections. Because of proximity of neurovascular structures around the tendon, iatrogenic injury to them have been a concern about this technique. The sural nerve (SN) is under risk of injury at the site of the lateral incomplete cut, especially if it is done proximally. The medial neurovascular bundle is under injury risk at medial cuts. The aim of the article was to study the anatomical relations of the SN and medial neurovascular bundle to the AT, and define dangerous levels for injury with the help of magnetic resonance imaging (MRI).

METHODS

Patients operated for percutaneous Achilles lengthening were called for MRI investigation of the SN and medial neruvascular bundle integrity and their anatomical relation with the AT. The distance of 5 mm was taken as the threshold for increased risk of injury. Measurements were done on MRI at each cm from the insertion of the tendon on both medial and lateral sides, and at the level of the middle cut.

RESULTS

Thirty ankles operated and followed at least 1 year were included to the study. On the medial side, the tibial nerve, and the posterior tibial artery lied more than 5 mm away from the tendon at all levels in all patient. On the lateral side, the first 4 cm were relatively safe for the middle lateral cut, while increased risk of SN damage was detected in more proximal levels. Overall, 6 of 30 ankles had radiographically detectable SN injury.

CONCLUSIONS

The first 4 cm of the AT on the lateral side was detected to be safe for the middle lateral directed cut, while whole tendon length were found to be safe for the first and the third cuts of the percutaneous Achilles lengthening surgery using 3 hemisections in children with cerebral palsy.

LEVEL OF EVIDENCE

Level III.

Treatment of Severe Rigid Posttraumatic Equinus Deformity With Gradual Deformity Correction and Arthroscopic Ankle Arthrodesis

BACKGROUND

Posttraumatic ankle equinus is associated with rigid deformity, poor skin condition, and multiple prior surgeries. Open acute correction has been described using osteotomies, talectomy, and arthrodesis, but concerns exist about skin complications, neurologic alterations, secondary limb discrepancy, and bone loss. Gradual correction using a multiplanar ring fixator and arthroscopic ankle arthrodesis (AAA) may decrease these complications.

METHODS

We retrospectively reviewed patients undergoing correction of posttraumatic rigid equinus with at least 1 year of follow-up after frame removal. The procedure consisted of percutaneous Achilles lengthening, gradual equinus correction using a multiplanar ring fixator, and AAA retaining the fixator in compression with screw augmentation. Frame removal depended on signs of union on the computed tomography scan. Visual analog scale (VAS) and Foot Function Index (FFI) scores were assessed as well as preoperative and postoperative x-rays. Complications were noted throughout the follow-up period.

RESULTS

Five patients were treated with a mean age of 35 years and mean follow-up of 31 months. Deformities were gradually corrected into a plantigrade foot over an average duration of 6 weeks. Union was achieved in all patients with a mean time of an additional 25 weeks, for a mean total frame time of 31 weeks. The mean preoperative tibiotalar angle was 151 degrees and was corrected to 115 degrees. FFI score improved from a mean of 87 to 24 and VAS from 8 to 2.

CONCLUSION

Posttraumatic rigid equinus can be treated effectively using gradual correction followed by integrated AAA in a safe and reproducible manner. Patients in this series had excellent functional, radiological, and satisfaction results.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

Operative management of equinus associated with lower limb venous malformations

OBJECTIVES

Functional impairment is a common complaint in patients with venous malformations. Equinus can occur when the venous malformation involves the lower limb, a challenging condition with only a few studies to guide treatment choices. This study was aimed to investigate the operative management of equinus associated with lower limb venous malformations.

METHOD

Between August 2015 and September 2017, a total of 12 patients presented with equinus associated with lower limb venous malformations and underwent surgical correction. Preoperative and postoperative clinical symptoms, physical examination and orthopaedic evaluation were retrospectively reviewed. 8 patients who experienced pain underwent percutaneous sclerotherapy prior to the operation. Surgical management included gastrocnemius intramuscular aponeurotic recession, Z-lengthening of the Achilles tendon, Hoke technique and Taylor Spatial Frame external fixation.

RESULTS

There were eight female and four male patients with a mean age of 14.3 ± 5.9 years. The mean follow-up period was 34.8 ± 9 months. The range of motion of ankle dorsiflexion (with knee extended) improved for each patient (mean, 25.4 degrees; standard deviation, 8.5 degrees). No neurovascular complications were observed.

CONCLUSION

Operative correction of equinus associated with lower limb venous malformations is safe and effective. Selective preoperative sclerotherapy is necessary for optimal outcomes.

A high-profile thread with grit-blasted and acid-etched surface reduces loosening of medial column fusion bolt in instable Charcot foot

BACKGROUND

Intramedullary fusion bolts (FB) were introduced to stabilize the medial column of the instable Charcot foot (ICF), but complications as bolt loosening or breakage are frequent. We compared the use of a standard FB and a high-profile threaded FB with a grit-blasted surface. We hypothesized that implant related complications occurred less often and osseous consolidation of fusion sites was more distinctive using the latter type of FB.

METHODS

Consecutive patients suffering from an ICF were stabilized with a high-profile threaded and surface-modified FB (HTFB) (n=20) or with a standard FB (n=20) which was placed into the first ray. Additional bolts and dorsal low-profile plates were applied in every patient. In a retrospective assessment osseous consolidation of the fusion sites was analyzed at 3 month and quantified by CT scan. At 3 and 12 month longitudinal foot arch collapse and rate of bolt loosening were assessed.

RESULTS

Compared to the control group, the HTFB group reached significant higher consolidation after 3 month. No dislocation and a single bolt breakage was observed in the HTFB group after the fourth month, while the control group included 3 patients with bolt dislocation at 3±1 month and 5 patients with bolt breakage at 6±1.8 month. Compared to preoperative values, the improvement of Meary's angle after one-year was significant higher in the HTFB group (23.4°±14) than in controls (11.7°±13).

CONCLUSIONS

Modification of bolt design improves the stability of the medial column: A higher rate of osseous consolidation of the medial column leads to lower rate of bolt dislocation/breakage and finally to permanently erected longitudinal foot arch. Initially disappointing results following medial column stabilization with fusion bolts can be rejected by modifications of bolt design and its technical application.

Tendon lengthening after achilles tendon rupture-passive effects on the ankle joint in a cadaveric pilot study simulating weight bearing

BACKGROUND

In recent years, primary Achilles tendon ruptures have increased due to the aging population's participation in physically demanding activities. These injuries commonly occur during recreational sports and frequently lead to a long-term reduction in activity despite treatment. Non-operative methods of treatment for Achilles tendon ruptures may result in the Achilles healing in a lengthened position compared to the pre-injury state. This study uses a cadaveric model that simulates static weight bearing to explore the effect of a lengthened Achilles tendon on ankle joint load distribution.

METHODS

Five lower limb cadaveric specimens were placed on a custom jig, where a 334 N (75 lb) load was applied at the femoral head, and the foot was supported against a plate to simulate static double-leg stance. A pressure mapping sensor was inserted into the ankle joint. A percutaneous triple hemiresection tendo-Achilles lengthening procedure (Hoke procedure) was performed on each specimen to simulate tendon lengthening after conservative treatment. Contact pressure, peak pressure, and center-of-pressure were measured for native and tendon-lengthened conditions.

RESULTS

Tendon rupture did not significantly alter average contact pressure, peak contact pressures, or center-of-pressure in the ankle joint compared with native tendon.

CONCLUSION

Achilles lengthening does not significantly change contact pressures of the ankle joint in this model . This result suggests that the passive restraint on ankle joint translation imposed by the Achilles tendon is minimal without muscle activation.

Percutaneous Hamstring Lengthening Surgery is as Effective as Open Lengthening in Children With Cerebral Palsy

BACKGROUND

Surgical lengthening of the hamstrings is often performed to correct crouch gait in children with cerebral palsy (CP). Previous studies have demonstrated the effectiveness of open hamstring lengthening (oHSL) in improving knee extension static and dynamic range of motion; however, literature regarding percutaneous hamstring lengthening (pHSL) is limited. The purpose of this study was to investigate the effect of open versus pHSL for improving crouch gait and knee function in children with CP.

METHODS

This retrospective cohort study included 87 ambulatory children with CP who underwent HLS surgery with both preoperative and postoperative gait analysis (mean time, 29.4±19.9 mo after surgery) testing between 1997 and 2015. In total, 65 patients underwent oHLS surgery (mean age, 8.5±2.5 y) and 22 patients underwent pHSL surgery (mean age, 8.3±2.3 y). Lower extremity three-dimensional kinematic data were collected while subjects walked at a self-selected speed. Outcome variables for operative limbs were compared within and between groups using t tests, χ tests, and multiple regression analysis.

RESULTS

Significant postoperative decreases in knee flexion at initial contact were seen for both open (Δ12.7±13.4 degrees; P<0.001) and percutaneous (Δ19.1±13.1 degrees; P<0.001) groups. Increased postoperative maximum knee extension in stance was found for both open (Δ8.2±16.8 degrees; P=0.001) and percutaneous (Δ14.4±16.5 degrees; P=0.001) groups. No significant differences between open and percutaneous groups were found when comparing postoperative changes in kinematic variables between groups after adjusting for covariates. Postoperative changes in static range of motion were similar between lengthening groups.

CONCLUSIONS

pHSL is as effective as open lengthening in improving stance phase knee kinematics during gait in children with CP. This is the first study to compare the kinematic effects of open versus pHSL in the pediatric population. Percutaneous lengthening is tolerated well by patients, and as it allows for rapid rehabilitation it may be preferable to the open procedure.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.

Critical evaluation of the surgical techniques to correct the equinus deformity

The equinus deformity causes changes in the foot contact and may affect more proximal anatomical regions, such as the knee, hip and trunk, potentially leading to gait disorders. The equinus is usually secondary to retraction, shortening and/or spasticity of the triceps surae, and it may require surgical correction. Surgery for the correction of equinus is one of the oldest procedures in Orthopedics, and it was initially performed only at the calcaneus tendon. The technique has evolved, so that it could be customized for each patient, depending on the degree of deformity, the underlying disease, and patient´s profile. The aim is to correct the deformity, with minimal interference in muscle strength, thus reducing the incidence of disabling complications such as crouch gait and calcaneus foot. We conducted a literature search for the most common surgical techniques to correct the equinus deformity using classic books and original articles. Further, we performed a database search for articles published in the last ten years. From the anatomical perspective, the triceps surae presents five anatomical regions that can be approached surgically for the equinus correction. Due to the complexity of the equinus, orthopedic surgeons should be experienced with at least one procedure at each region. In this text, we critically approach and analyze the most important techniques for correction of the equinus, mainly to avoid complications.

Use of 3D gait analysis as predictor of Achilles tendon lengthening surgery outcomes in children with cerebral palsy

BACKGROUND

In children with spastic cerebral palsy (CP), the treatment of equinus foot with Achilles tendon lengthening (ATL) surgery is associated with high incidence of overcorrection, which may result in crouch gait.

AIM

We aimed to assess if gait pattern in preoperative time could be a predictor of the surgery outcome.

DESIGN

Cross-sectional retrospective study.

SETTING

Movement Analysis Lab of IRCCS San Raffaele Pisana Hospital in Rome (Italy).

POPULATION

Eighteen children (mean age 9.6±4.7 years) with spastic diplegia CP who underwent bilateral ATL surgery to correct equinus foot were involved.

METHODS

Participants underwent 3D gait analysis before and approximately 12 months after surgery. Primary measures were spatiotemporal, kinematic (summarized by Gait Variable Scores, GVSs) and kinetic parameters. The gait patterns for each leg was defined from kinematic data, using a quantitative classification: plantar flexor knee extension (PFKE) index. The CP group was split into true equinus and jump gait.

RESULTS

The equinus foot was successfully corrected as demonstrated by the improvement of GVS ankle dorsi-plantarflexion. However, there was a high rate of overcorrection in the true equinus, characterized by increases in knee flexion-extension GVS (8.7° pre vs. 16.7° post P<0.05) and knee flexion angle at initial contact (5.2° vs. 20.6° P<0.05) and by a decrease in the maximum ankle power generated at push-off (1.49 vs. 0.83 W/kg P<0.05).

CONCLUSIONS

Assessment of motor phenotype in preoperative time are good predictors of the results of ATL surgery. In children with true equinus gait, the increase of knee flexion subsequent to ATL is an early indicator that this technique will lead to crouch gait. These results show the influence of true equinus and jump gait patterns on the outcomes of the ATL.

CLINICAL REHABILITATION IMPACT

Therefore, we propose that this approach could have clinical value to evaluate and prescribe rehabilitation in children with CP disease, proposing different solutions depending on motor phenotype.

Ultrasonography of the Sural Nerve: Normal and Pathologic Appearances

Ultrasonography (US) of peripheral nerves has gained wide popularity because of the increased definition of modern high-frequency electronic transducers, as well as the well-known advantages of US, which include easy availability, low cost, and the possibility of realizing a dynamic examination. Traditionally, US has been deployed to assess the major nerves of the limbs. More recently, US has also been used to assess the normal appearance and pathologic changes of smaller subcutaneous nerves. The sural nerve is a small sensory nerve in the subcutaneous tissues of the calf that can be affected by a variety of disorders. This pictorial essay illustrates the normal anatomy of the sural nerve, the technique for its examination by US, as well as the US appearance of its main pathologic changes.

Anatomic Evaluation of Percutaneous Achilles Tendon Lengthening

BACKGROUND

The objective of the study was to evaluate the accuracy of percutaneous Achilles tendon lengthening (TAL) using a triple hemisection technique and the improvement in ankle dorsiflexion.

METHODS

Ten fresh-frozen above-knee cadaveric specimens were used. A percutaneous triple hemisection of the Achilles tendon (proximal, intermediate, and distal) was performed. Maximum ankle dorsiflexion was evaluated pre- and postprocedure with a digital goniometer. After proper dissection, the relative width of the cuts was noted. Following forced ankle dorsiflexion, displacement in the tensile gaps was measured in all 3 cuts with a precision digital caliper.

RESULTS

The overall relative width of the percutaneous cut was 51.3% ± 16.3% of the Achilles tendon diameter, 44.3% ± 13.6% for the proximal cut, 50.3% ± 15.6% for the intermediate cut, and 59.3% ± 18.4% for the distal cut. Tendon excursion averaged 13.0 ± 3.8 mm for the proximal cuts, 12.5 ± 4.7 mm for the intermediate cuts, and 8.2 ± 3.7 mm for the distal cuts. One cadaver had a complete rupture of the Achilles tendon and was excluded from the excursion data analysis. The mean range of motion for ankle dorsiflexion was 8.1 ± 3.9 degrees preprocedure and 27.6 ± 5.3 degrees postprocedure. The dorsiflexion angle significantly increased ( P < .0001) at an average of 19.5 ± 5.0 degrees following TAL.

CONCLUSION

Our cadaveric study demonstrated that the percutaneous triple hemisection of the Achilles was an accurate technique that provided successful lengthening of the tendon and increased ankle dorsiflexion. Complete ruptures are possible complications.

CLINICAL RELEVANCE

Our cadaveric study showed that in a clinical situation, triple hemisections of the Achilles tendon can be performed reliably, with significant improvement of the ankle dorsiflexion, mainly through increased tendon excursion at the proximal and intermediate cuts, and with low risk of complete ruptures.

Dealing with the Stiff Ankle: Preoperative and Late Occurrence

In patients with a stiff ankle replacement, appropriate resection of scarred capsular structures, hypertrophic bone debridement, and careful release of tendons should be performed to achieve good outcomes. Appropriately sized and correctly implanted components are required to restore ankle function to as normal as possible. Although not proven, the better a total ankle replacement is balanced, the less likely scar and heterotopic bone formation will occur. In patients with a stiff and painful ankle replacement, a preoperative diagnostic workup is mandatory to understand the underlying pathologic process and plan appropriate treatment. All underlying causes should be addressed.

Equinus and Lengthening Techniques

Equinus is linked to most lower extremity biomechanically related disorders. Defining equinus as ankle joint dorsiflexion less than 5° of dorsiflexion with the knee extended is the basis for evaluation and management of the deformity. Consistent evaluation methodology using a goniometer with the subtalar joint in neutral position and midtarsal joint supinated while dorsiflexing the ankle with knee extended provides a consistent clinical examination. For equinus deformity with an associated disorder, comprehensive treatment mandates treatment of the equinus deformity. Surgical treatment of equinus offers multiple procedures but the Baumann gastrocnemius recession is preferred based on deformity correction without weakness.

Calcaneal Z Lengthening Osteotomy Combined With Subtalar Arthroereisis for Severe Adolescent Flexible Flatfoot Reconstruction

BACKGROUND

The timing and strategy for operative treatment of flatfoot are still controversial. The purpose of this study was to evaluate clinical outcomes and radiographic changes following calcaneal Z osteotomy combined with subtalar arthroereisis for severe adolescent flexible flatfoot.

METHODS

Data were analyzed for 16 patients (20 feet) who had flatfoot without tibialis posterior tendon dysfunction and were treated by calcaneal Z osteotomy combined with arthroereisis between October 2011 and February 2015. The mean age of patients at the time of surgery was 12.8 ± 1.4 years (range, 10-14 years). Preoperative and postoperative measurements included changes in hindfoot valgus angles; changes in talonavicular uncoverage angles on anteroposterior (AP) radiographic view; and changes in talo-first metatarsal angles, talar pitch angles, and calcaneal pitch angles on lateral radiographic view. The American Orthopaedic Foot & Ankle Society Ankle-Hindfoot Score (AOFAS-AH) was used to assess foot function. The mean follow-up was 18.9 ± 6.9 months (range, 13-33 months).

RESULTS

The hindfoot valgus angle improved from 14.9 ± 4.2 degrees to 2.3 ± 1.7 degrees. On the AP view, the preoperative and postoperative talonavicular uncoverage angles were 30.5 ± 9.4 degrees and 9.8 ± 4.8 degrees, respectively. On lateral radiographs, the preoperative talo-first metatarsal angle, talar pitch angle, and calcaneal pitch angle were -22.1 ± 7.9 degrees, 36.1 ± 4.4 degrees, and 14.4 ± 4.0 degrees, respectively. Postoperative lateral radiographs demonstrated talo-first metatarsal angle, talar pitch angle, and calcaneal pitch angle of -6.2 ± 4.7 degrees, 27.3 ± 4.9 degrees, and 19.0 ± 4.3 degrees, respectively. The AOFAS-AH score improved from 66.8 ± 24.1 preoperatively to 96.5 ± 3.4 postoperatively.

CONCLUSIONS

For adolescents with flatfoot, calcaneal Z osteotomy combined with subtalar arthroereisis provided satisfactory results.

LEVEL OF EVIDENCE

Level IV, retrospective case series.

The influence of timing of knee recurvatum on surgical outcome in cerebral palsy

Recent reports have shown that timing of genu recurvatum (GR) might be caused by different underlying factors and that equinus leads to GR especially during early stance. The purpose of this study was to investigate the reduction of GR after surgical correction of equinus in children with bilateral spastic cerebral palsy and whether the children with early and late type GR show differences in reduction of knee hyperextension after a surgery. In 24 limbs (mean age 10.3 years, GMFCS I-III) showing equinus and GR the kinematics of the knee and ankle as well as the kinetics of the knee were evaluated before and one year (mean follow up period: 12.8 months) after surgical correction of equinus. The study was approved by the local ethical committee. Limbs with early type GR showed a reduction by 11.1° (p<0.001) and those with late type GR by 6.0° (p<0.049) in GR after surgery. Before surgery limbs with early type GR showed increased external extending moments, which decreased significantly after surgery. In contrast limbs with late GR did not show a significant reduction of those moments. The findings of this study underline the influence of equinus on early GR as an underlying factor. As equinus is attributed to early knee hyperextension and proximal factors are more important as underlying factors in late type GR, a classification into early and late onset GR is useful to identify underlying factors and to choose adequate treatment.

Is percutaneous proximal gracilis tenotomy as effective and safe as the open procedure?

PURPOSE

There is currently an increasing trend for percutaneous surgical interventions mainly in children with cerebral palsy (CP). The purpose of this study was to evaluate the effectiveness and safety of percutaneous proximal gracilis tenotomy (PPGT) in children with CP scheduled for hip adductor tenotomy.

METHODS

This is a prospective study of 59 hips in 31 consecutive patients with CP scheduled for hip adductor tenotomy in the setting of multilevel tenotomies or hip osteotomy (femoral or Dega). A pediatric orthopedic surgeon conducted a percutaneous adductor longus and gracilis tenotomy through the same stab wound. Another surgeon extended the wound to explore what had been cut during the PPGT, and completed the tenotomy if necessary (open proximal gracilis tenotomy; OPGT). Hip abduction with the hip and knee extended (HA) was assessed by a third surgeon (1) immediately before PPGT, i.e., directly after percutaneous adductor longus tenotomy (prePPGT), (2) after PPGT (postPPGT), and (3) following OPGT (postOPGT), using a goniometer, in a standardized reproducible manner. All three surgeons were blinded to each other's findings. Primary end-points included the percentage of muscle portion sectioned percutaneously and the improvement of HA angle. Comparison between HA before and after PPGT was performed using a paired t test with 95 % confidence interval (CI), and comparison between HA after PPGT and OPGT was performed using a Student's t-test with 95 % CI. The bleeding was assessed and other iatrogenic lesions were identified. The relationship between HA after PPGT and the percentage of muscle portion sectioned percutaneously was evaluated by calculating the Pearson correlation coefficient (p < 0.01).

RESULTS

Mean HA measured 33.71 degrees prePPGT and increased to 45.90 degrees postPPGT (p < 0.0001). The postOPGT HA averaged 48.71 degrees with no statistically significant gain compared with postPPGT (p = 0.21). The muscular portion of gracilis origin was cut to an average of 91.95 %; completely in only 14 hips, between 90 and 100 % in 35 hips, between 70 and 90 % in 9 hips, and between 60 and 70 % in 1 hip. The gain in HA did not correlate with the extent of the muscular portion sectioned percutaneously (R = -0.043). Minimal accidental section of adductor brevis postPPGT was encountered in 39 hips. Considerable bleeding postPPGT with hematoma formation requiring hemostasis during the open control procedure occurred in 30 hips. Partial iatrogenic injury of the anterior branch of the obturator nerve was encountered in one patient bilaterally with severe adductor contracture, due to an anatomic too medial variant.

CONCLUSIONS

This is the only prospective study concerning the outcome of PPGT. Although PPGT is fast, simple and effective, it is not as safe as the open procedure even when performed correctly by an experienced surgeon, mainly because of the increased risk of bleeding. The findings of the current study do not support its use as a 'standard-of-care' technique in children with hip adductor contracture.

LEVEL OF EVIDENCE

Level II therapeutic study-prospective comparative study.

Treatment of Severe Recurrent Clubfoot

Understanding the pathoanatomy of severe recurrent clubfoot and its implication on treatment options is important for the successful treatment. A comprehensive clinical evaluation of the different components helps in selecting procedures. Individual needs and social and psychological factors influencing treatment and the impact of treatment on the child have to be considered. With increasing dissemination and improved understanding of the Ponseti method, a further decrease in the frequency of severe recurrent clubfoot can be hoped for and expected.

Shear loads induce cellular damage in tendon fascicles

Tendon is vital to musculoskeletal function, transferring loads from muscle to bone for joint motion and stability. It is an anisotropic, highly organized, fibrous structure containing primarily type I collagen in addition to tenocytes and other extracellular matrix components contributing to maintenance and function. Tendon is generally loaded via normal stress in a longitudinal direction. However, certain situations, including fiber breakage, enzymatic remodeling, or tendon pathology may introduce various degrees of other loading modalities, such as shear-lag at the fiber level, potentially affecting cellular response and subsequent function. Fascicles from rat tail tendon were dissected and placed in one of three paired groups: intact, single laceration, or double laceration. Each pair had a mechanically tested and control specimen. Single laceration fascicles contained one transverse laceration to mimic a partial tear. Double laceration fascicles had overlapping, longitudinally separated lacerations on opposite sides to cause intra-fascicular shear transfer to be the primary mechanism of loading. Elastic properties of the fascicle, e.g. peak load, steady state load, and stiffness, decreased from intact to single laceration to double laceration groups. Surprisingly, 45% of the intact strength was maintained when shear was the primary internal load transfer mechanism. Cellular viability decreased after mechanical testing in both laceration groups; cell death appeared primarily in a longitudinal plane where high shear load transfer occurred. This cell death extended far from the injury site and may further compromise an already damaged tendon via enzymatic factors and subsequent remodeling associated with cell necrosis.

Shear load transfer in high and low stress tendons

BACKGROUND

Tendon is an integral part of joint movement and stability, as it functions to transmit load from muscle to bone. It has an anisotropic, fibrous hierarchical structure that is generally loaded in the direction of its fibers/fascicles. Internal load distributions are altered when joint motion rotates an insertion site or when local damage disrupts fibers/fascicles, potentially causing inter-fiber (or inter-fascicular) shear. Tendons with different microstructures (helical versus linear) may redistribute loads differently.

METHOD OF APPROACH

This study explored how shear redistributes axial loads in rat tail tendon (low stress tendons with linear microstructure) and porcine flexor tendon (high stress with helical microstructure) by creating lacerations on opposite sides of the tendon, ranging from about 20% to 60% of the tendon width, to create various magnitudes of shear. Differences in fascicular orientation were quantified using polarized light microscopy.

RESULTS AND CONCLUSIONS

Unexpectedly, both tendon types maintained about 20% of pre-laceration stress values after overlapping cuts of 60% of tendon width (no intact fibers end to end) suggesting that shear stress transfer can contribute more to overall tendon strength and stiffness than previously reported. All structural parameters for both tendon types decreased linearly with increasing laceration depth. The tail tendon had a more rapid decline in post-laceration elastic stress and modulus parameters as well as a more linear and less tightly packed fascicular structure, suggesting that positional tendons may be less well suited to redistribute loads via a shear mechanism.

Gastrocnemius shortening and heel pain

Pain and reduced function caused by disorders of either the plantar fascia or the Achilles tendon are common. Although heel pain is not a major public health problem it affects millions of people each year. For most patients, time and first-line treatments allow symptoms to resolve. A proportion of patients have resistant symptoms. Managing these recalcitrant cases is a challenge. Gastrocnemius contracture produces increased strain in both the Achilles tendon and the plantar fascia. This biomechanical feature must be properly assessed otherwise treatment is compromised.

Z-lengthening of the Achilles tendon with transverse skin incision

Background

The risk of various complications after Achilles tendon lengthening is mainly related to the length of surgical exposure and the lengthening method. A comprehensive technique to minimize the complications is required.

Methods

The treatment of Achilles tendon tightness in 57 patients (95 ankles) were performed by using a short transverse incision on a skin crease of the heel and by Z-lengthening of the tendon. In the severe cases, two or three transverse incisions were required for greater lengthening of the tendon, and a serial cast or Ilizarov apparatus was applied for the gradual correction. The results of these 95 ankles were compared to those of 18 ankles, which underwent percutaneous sliding lengthening, and to the 19 ankles, which received Z-lengthening with a medial longitudinal incision.

Results

The functional and cosmetic satisfaction was achieved among those who underwent the tendon lengthening with the new technique. The mean American Orthopaedic Foot & Ankle Society (AOFAS) score improved from 56.1 to 81.8. The second operations to correct recurrence were performed in the two cerebral palsy patients.

Conclusions

The new technique has a low rate of complications such as scarring, adhesion, total transection, excessive lengthening, and recurrence of shortening. The excellent cosmesis and the short operation time are the additional advantages.

Reduction in primary genu recurvatum gait after aponeurotic calf muscle lengthening during multilevel surgery

Knee hyperextension (genu recurvatum, GR) is often seen in children with bilateral spastic cerebral palsy (CP). Primary GR appears essential without previous treatment. As equinus deformity is suspected to be one of the main factors evoking primary GR, the purpose of this study was to determine whether lengthening the calf muscles to decrease equinus would decrease coexisting GR in children with bilateral spastic CP. In a retrospective study, 19 CP patients with primary GR (mean age: 9.4 years, 13 male, 6 female, 26 involved limbs) in whom an aponeurotic calf muscle lengthening procedure was performed during single-event multilevel surgery were included and investigated using three-dimensional gait analysis before and at a mean follow-up of 14 months after the procedure according to a standardized protocol. After calf muscle lengthening, a significant improvement in ankle dorsiflexion (9.5°) and a significant reduction (10.5°) in knee hyperextension (p<0.001) were found during mid-stance of the gait cycle. Six limbs (23%) showed no improvement concerning knee hyperextension and were designated as nonresponders. In these patients no significant improvement in ankle dorsiflexion was found after surgery either. Improvement in ankle dorsiflexion and reduction in knee hyperextension in stance phase correlated significantly (r=0.46; p=0.019). These findings indicate that equinus deformity is a Major underlying factor in Primary GR and that calf muscle lengthening can effectively reduce GR in patients with CP.

Total ankle replacement using HINTEGRA, an unconstrained, three-component system: surgical technique and pitfalls

Total ankle replacement (TAR) has become a valuable treatment option in patients with end-stage ankle osteoarthritis. One popular 3-component system, the HINTEGRA TAR, is an unconstrained system that provides inversion-eversion stability. More natural biomechanics of the replaced ankle may be expected when anatomic considerations drive prosthesis design. The HINTEGRA prosthesis includes 2 anatomically contoured metal components and a polyethylene insert, providing axial rotation and physiologic flexion-extension mobility. This article describes the HINTEGRA TAR design and surgical technique. Use of the prosthesis for complex hindfoot reconstruction in patients with an osteoarthritic, varus, or valgus ankle deformity is described.

Recurrence of diabetic pedal ulcerations following tendo-achilles lengthening

Foot and ankle surgeons are frequently challenged by the devastating systemic consequences of diabetes mellitus manifested through neuropathy, integumentary and joint breakdown, delayed healing, decreased ability to fight infection, and fragile tendon/ligaments. Diabetic neuropathic pedal ulcerations lead to amputations at an alarming rate and also carry a high mortality rate. This article will discuss causes of diabetic pedal ulcerations that persist or recur after tendo-Achilles lengthening and will highlight areas that need to be addressed by the practitioner such as infection, vascular and nutritional status, glucose control, off-loading, biomechanics, and patient compliance.

Functional outcome after percutaneous tendo-Achilles lengthening

BACKGROUND

Percutaneous tendo-Achilles lengthening (PTAL) is a common procedure performed as an adjunct to other procedures that are used to treat a variety of foot and ankle disorders. Despite the widespread use of PTAL, the only literature to substantiate its efficacy comes from the treatment of forefoot ulceration in diabetics. The complications of the procedure include pain along the Achilles tendon, difficulty using stairs, weakness with toe-off, inadvertent complete tenotomy, and cosmetic appearance. We sought to investigate the functional outcomes specific to PTAL when performed in tandem with triple arthrodesis and subtalar fusion.

MATERIALS AND METHODS

A retrospective review of 107 patients who underwent 117 procedures was performed. Outcomes were assessed by telephone interview using a standard questionnaire. The most common procedure in the study population was triple arthrodesis (91%).

RESULTS

Fifty-eight percent of the patients reported moderate improvement in motion postoperatively, but 80% reported some degree of persistent stiffness. Despite 38% of patients reporting postoperative weakness, 66% and 61% stated that ascending and descending stairs, respectively, was easier.

CONCLUSION

Overall, 81% of the study population had a positive opinion regarding their surgery. In this heterogeneous population, we showed modest improvement in Achilles tendon-related outcomes when PTAL was performed in tandem with other surgeries.

Is percutaneous adductor tenotomy as effective and safe as the open procedure?

BACKGROUND

Percutaneous adductor longus tenotomy (PAT) is a frequently used procedure, yet no study has ever compared its effectiveness and safety with those of open adductor longus tenotomy (OAT). We conducted this prospective study to describe the effects of PAT and to compare them with those of OAT.

METHODS

This consisted of a cross-over randomized controlled trial including 50 consecutive hips from 27 patients with cerebral palsy scheduled for adductor tenotomy in the setting of multilevel tendon lengthening/release procedures or hip surgery (femoral or Dega osteotomy) in a university hospital. A pediatric orthopaedic surgeon conducted a PAT. Another surgeon extended the wound to explore what had been cut during the PAT, and completed the tenotomy if necessary. Hip abduction (HA) was assessed by a third surgeon immediately before PAT, after PAT, and then after OAT, using a goniometer, in a standardized reproducible manner. All 3 surgeons were blinded to the others' findings. Primary end-points included the percentage of tendon/muscle portion sectioned percutaneously, and the HA measure. Comparison between HA after PAT and OAT was done using a paired t-test with a 95% confidence interval. The influence of anatomic variants of adductor longus origin was also assessed.

RESULTS

Mean HA (hips flexed) measured 40.36 degrees preoperatively and increased to 50.04 degrees after PAT (P<0.0001). After OAT, HA averaged 53.32 degrees with no statistical gain compared with that observed after PAT (P=0.2). The tendinous portion of adductor longus was cut to an average of 98% by PAT (completely in 46 cases and more than 75% in only 4 cases). The muscular portion of adductor longus origin was cut to an average of 83.7% (completely in only 15 cases, cut to more than 75% in 26 cases, and approximately 50% in 9 cases). The gain in HA positively correlated with the extent of the tendinous portion divided (P=0.03) but not with the extent of muscular portion divided. Results were independent of the anatomic variants of adductor longus origin. Partial section of adductor brevis after PAT was encountered in 6 cases. No major iatrogenic lesion was observed (obturator nerve, major vessels).

CONCLUSIONS

This is the only prospective study concerning the effects of PAT. The anatomic factor associated with gain in HA seems to be the extent of the section of the tendinous portion of adductor longus origin, which was found to be cut to more than 90% in all cases after PAT. The extent of muscular portion section does not seem to influence the gain in HA. The researchers detail the technique of percutaneous adductor tenotomy and show that when done correctly, PAT is a fast and simple procedure, as reliable and effective as the open release and without any major risks.

LEVEL OF EVIDENCE

Level II therapeutic study-prospective comparative study.

Idiopathic toe walking and contractures of the triceps surae

Toe walking is a common feature in immature gait and is considered normal up to 3 years of age. As walking ability improves, initial contact is made with the heel. Toe-walkers will stand out as different once heel-strike is achieved by most of their peers. This difference gives rise to parental concern. Therefore toe-walkers are often referred at 3 years of age. This article examines the evidence for the management of children who have idiopathic toe walking and reviews the literature on surgery for the lengthening of a calf contracture.

Surgical correction of soft-tissue ankle equinus contracture

Soft-tissue ankle equinus contracture is an important component of numerous foot and ankle deformities. In high-risk patients who have multiple co-morbidities, procedure selection and careful surgical technique are paramount to increase the likelihood of postoperative success. This article discusses the indications for percutaneous Achilles tendon lengthening, open gastrocnemius recession, and endoscopic gastrocnemius recession, and provides a detailed description of each surgical technique with pearls to avoid intra-perative and postoperative complications specific to the high-risk patient. Thorough knowledge of each of these techniques will aide the foot and ankle surgeon in appropriate peri-operative management of equinus deformity in a complex patient population.

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 <or=2 mm and/or a cut depth of <or=25% or <75%.

RESULTS

21 of the 60 hemisections failed. These failures occurred in 12 of the 20 legs, and included 1 complete tendon rupture and 3 near-ruptures with only a few connecting fibers left.

INTERPRETATION

Our findings support our hypothesis that technical failures in the triple hemisection procedure occur more often than acknowledged. Despite the scarce but good clinical results described in children, we suggest performing this technique as an open procedure, especially in cases where the boundaries of the tendon are less easily palpable (adults, obese children), and to use the largest possible distance between the hemisections.

The surgical management of equinus in the adult acquired flatfoot

Ankle joint equinus plays a significant role in the pathogenesis of adult and pediatric flatfoot. The surgical management of ankle equinus is a widely debated topic, and procedure selection is often based on surgeon preference because there is no consensus regarding the superiority of a single procedure. Gastrocnemius recession offers acceptable cosmesis and minimizes perceived weakness, yet requires increased operating time and is indicated only in mild to moderate contractures. Whereas tendo-achilles lengthening is efficient and technically undemanding, and one may achieve large amounts of required length, final length is sometimes unpredictable and may markedly decrease posterior muscle group strength.