Split Tendon Research Articles

Effect of Attachment Site and Routing Variations in Split Tendon Transfer of Tibialis Posterior

Effect of Attachment Site and Routing Variations in Split Tendon Transfer of Tibialis Posterior

Biceps tenodesis: a biomechanical study of fixation methods

Rupture of the biceps tendon occurs predominantly in the middle-aged and elderly, being predisposed through bicipital tendinitis and rotator cuff lesions. Surgical repair may be an option for those requiring strength in supination. This study compared the initial fixation strength of keyhole tenodesis (n = 7) and interference screw fixation by use of cadaveric specimens. Two interference screws were evaluated (n = 7 × 2): the round-headed cannulated interference screw (RCI) and a bioresorbable screw (Sysorb). All specimens failed at the fixation site but one. This study found that overall there was a significant effect as a result of study group (keyhole vs Sysorb vs RCI, P = .034). The post hoc comparisons revealed that the keyhole was significantly stronger than the RCI screw ( P = .033) but not significantly different compared with the Sysorb screw ( P = .129). No significant difference was observed between the Sysorb and RCI screws ( P = .762). Interference screw fixation failed by tendon slippage at the screw-tendon-bone interface; keyhole fixation failed by tendon splitting and slippage out of the restraining keyhole. Keyhole tenodesis may permit earlier postoperative mobilization when compared with tenodesis by use of interference screw fixation.

Effect of attachment site and routing variations in split tendon transfer of tibialis posterior.

Spastic equinovarus is a condition that commonly affects the gait of children with cerebral palsy. Split tendon transfers of the tibialis posterior (TP) are often performed to eliminate the excessive hindfoot inversion present in equinovarus. TP muscle moment arms were computed before and after three variations of split TP tendon transfer to assess the effectiveness of each. The three surgeries tested were (1) the original split TP transfer to the distal peroneus brevis tendon routing behind the lateral malleolus; (2) an attachment variation in which the transferred tendon half was attached to the proximal peroneus brevis tendon rather than to the distal site; and (3) a routing variation in which the transferred tendon half was passed through a window in the interosseous membrane and attached to the distal peroneus brevis tendon. Tendon tension was controlled for in these experiments because improper tensioning is often cited as a reason for poor outcomes. All three surgeries significantly reduced the ability of TP to invert the hindfoot, thus eliminating a potential deforming force, but the reduction following interosseous routing was significantly less than that found for the other two transfer procedures. Routing through the interosseous membrane also reduced the ability of the TP to plantarflex the foot, but ankle actions were preserved following the other two surgeries. Routing through the interosseous membrane to an anterior attachment site resulted in a muscle with minimal potential to create or resist action about the ankle joint. Similar moment arms were measured when the attachment site on the peroneus brevis tendon was located either proximally or distally, suggesting that this choice does not appear to significantly affect the mechanical outcome.

Effects of tensioning errors in split transfers of tibialis anterior and posterior tendons.

Split transfers of the tibialis anterior and posterior tendons are commonly performed to address hindfoot varus deformities in patients with cerebral palsy, stroke, or brain injury. Poor outcomes from these procedures are often attributed to a failure to tension the transferred tendon properly, but the mechanical effects of this aspect of the procedure have not been quantified, to our knowledge. The purpose of the present study was to use a cadaver model to examine changes in the actions of these muscles that occur when the tensions in the halves of the split tendon are intentionally balanced or unbalanced to varying degrees. Tendon excursion was measured in seven cadaveric specimens before and after split tendon transfer with experimentally controlled tensions in the halves of the split tendon. The muscle moment arm, a quantitative indicator of the action of a muscle about a joint axis, was calculated as the derivative of tendon excursion with respect to the subtalar joint angle. The tibialis anterior had an eversion moment arm with the subtalar joint in a neutral position following surgery, but the tibialis posterior had virtually no action in the neutral position. Following the split transfers with ideally balanced tension, subtalar joint rotations of >5 degrees strongly influenced the moment arm of the tibialis posterior (p < 0.0002), indicating that its action depends on the position of the hindfoot. The moment arm of the tibialis anterior, however, was influenced only by rotations of >/=20 degrees (p > 0.1741 for each angle pair comparison of <20 degrees ). Moment arms were generally insensitive to imbalances in tension between the medial and lateral tendon halves; significant differences in the moment arm (p < 0.05), compared with that in the balanced condition, were seen only when one half was slack or nearly so. These results suggest that it is possible for a split tendon transfer to be successful over a large range of tensionings. Split transfer of the tibialis posterior tendon produced the desired mechanical outcome in that the tibialis posterior had an eversion moment arm when the foot was inverted and an inversion moment arm when the foot was everted. Split transfer of the tibialis anterior to the cuboid, however, produced a muscle that consistently functioned as an everter regardless of the position of the hindfoot.

Long-Term Follow-up of Surgery for Equinovarus Foot Deformity in Children With Cerebral Palsy

The factors associated with failed operative intervention in the treatment of equinovarus foot deformity in children with cerebral palsy (CP) were evaluated after long-term follow-up. One hundred eight children with CP who had surgery on the posterior tibialis tendon (split tendon transfer, intramuscular lengthening, or Z-lengthening) on 140 feet were reviewed at a mean age of 16.8 years with 7.3 years of follow-up. The surgery was considered a failure when a 10 degrees or greater varus or valgus hindfoot deformity was present or if an additional operative intervention was required or planned. Involvement of CP, age at operation, and preoperative status of ambulation were significant factors in the outcome of the surgery. Hemiplegic patients demonstrated the best results, regardless of age or surgical procedure. Seventy-five percent of diplegic and quadriplegic patients who were younger than 8 years or who were not capable of community ambulation failed operative intervention, and surgery on the posterior tibialis tendon is not recommended in this group of patients.

Recognition of the flexor digitorum accessorius longus.

The flexor digitorum accessorius longus muscle was observed during a cadaveric surgery course on the foot and ankle for third-year podiatric medical students. The cadaveric foot had been amputated just proximal to the ankle level so that the muscle origin could not be determined; its insertion, however, was found to be into the flexor digitorum longus tendon, just before the tendon split into its digital slips. This article reviews the literature on the muscle and its clinical implications and describes and shows the muscle as it was seen in this case.

Interference screw fixation of tendontransfers in the foot and ankle.

Tendon transfers pptay an important role in reconstructive foot and ankle surgery. Multiple methods for fixation of tendon to bone are used including suture of tendon to periosteum, suture into bone troughs, suture anchors, and passage through bone tunnels. With the increasing populatity of hamstring tendon anterior cruciate ligament reconstructions has come new fixation technology. Soft-tissue interference screws have been introduced that allow fixation of tendons into bone tunnels without the need for bone blocks.' Bioabsorbable versions of these screws have been shown to have equivalent or areater initial fixation than their titanium count em art^.^,^ We have recently begun using soft-tissue inierference screw fixation for tendon transfer in the foot. Our initial biomechanical studies in a foot and ankle model suggest its efficacy. Our originaf indication for use of an interference screw was graft length limitation. As part of our reconstruction for posterior tibial tendon insufficiency, we commonly transfer the flexor digitorum longus through a bone tunnef in the navicular, and suture the tendon back to itself. fn a case where sufficient length was not available, rather than rely on the tendon sewn to periosteum, we achieved fixation with a biodegradable interference screw. Since that time, we have confirmed the strength of this fixation method with a biomechanicai study? Several additional tendon transfers have been fixed with this technique without complication. Transfer of the posterior tibial tendon through the interosseus membrane for drop foot and split anterior tibial tendon transfer are also potential indications for interference screw fixation of the tendon transfer in the bony tunnef, Commonly, fixation for these transfers involves the use of felt and a button on the plantar aspect of the foot.5 The tension required can result in

Long-term results of superior oblique tendon elongation for Brown's syndrome.

To evaluate superior oblique tendon lengthening technique in the treatment of congenital Brown's Syndrome. Retrospective evaluation of 8 patients with Brown's syndrome (ages 2.5 to 8 years) who underwent superior oblique split tendon elongation as the primary procedure. The mean follow-up period was 35 months (range 18 to 72 months). Seven of 8 patients had complete resolution of the compensatory head posturing and downshoot in adduction, and achieved some ability to elevate the eye in adduction. One of the operated eyes required reoperation because head posture persisted and a tenectomy of the superior oblique tendon was performed with satisfactory results. The superior oblique split tendon lengthening technique is proposed as a possible procedure of choice for the treatment of Brown's syndrome.

Insertional Achilles tendinosis: surgical treatment through a central tendon splitting approach.

Twenty-two heels in 21 patients treated surgically for a primary diagnosis of insertional Achilles tendinosis were reviewed on the basis of preoperative and postoperative examinations, office records, and a comprehensive questionnaire administered to each subject. Each patient underwent surgical treatment using a midline-posterior skin incision combined with a central tendon splitting approach for debridement, retrocalcaneal bursectomy, and removal of the calcaneal bursal projection as necessary. The findings at surgery revealed involvement of the middle third of the insertion in 21 of 22 cases with only one patient manifesting isolated lateral involvement. Thirteen of 22 had an associated prominent calcaneal bursal projection and four of 22 a superficially inflamed bursa. Three patients required reinsertion of the tendo Achilles via drill holes and one underwent augmentation with a plantaris tendon. Operative findings and complications were reported. Eight male and 13 female patients underwent 22 procedures (one case bilaterally) with an average follow-up of 33 months. Preoperative symptoms include presence of symptoms over a range of three months to two years and pain associated with activities of daily living (17 of 22), limitation of regular activities (six of 22), and pain present at rest in six of 22. Postoperatively, 20 of 22 patients were able to return to work or routine activities by three months; only 13 of 22 were completely pain free. Only 13 of 22 also claimed that they were able to return to unlimited activities. Overall, there was an 82% (18 of 22) satisfaction rate with surgery and 77% (17 of 22) stated they would have the surgery again.

Changes in muscle moment arms following split tendon transfer of tibialis anterior and tibialis posterior.

Moment arms of tibialis anterior (TA) and tibialis posterior (TP) about the subtalar and talocrural joint axes were measured in anatomic specimens both before and after split tendon transfers. These procedures are commonly performed to correct hindfoot varus, a gait deformity that is often seen in patients with cerebral palsy, stroke, and brain injury. Split tendon transfer significantly reduced the inversion moment arms of tibialis anterior and tibialis posterior at all subtalar joint angles except for the most everted position in the case of TA. Changes in subtalar joint moment arms produced by split tendon transfer, especially those seen in TA, were variable, suggesting that the procedure may be susceptible to technical errors, especially related to balancing tensions in the medial and lateral tendon halves. Talocrural joint moment arms of both muscles were preserved following split tendon transfer. This study presents the first measurements of the moment arms of split transferred muscles. These characterizations of the mechanics of split tendon transfer will aid in the planning and assessment of these procedures.

Split tibialis posterior tendon transfer with concomitant distal tibial derotational osteotomy in children with cerebral palsy.

Fifteen lower extremities with a spastic equinovarus foot deformity associated with internal tibial torsion were identified. Each lower extremity underwent a split tibialis posterior tendon transfer combined with a distal tibial derotational osteotomy. The medical record of each patient was reviewed retrospectively. We paid particular attention to clinic visits, gait analyses, and surgical procedures performed. These patients were followed up for an average of 4 years and 5 months after surgery. Twenty-seven percent had an excellent result, 13% developed a rigid equinovarus deformity, and 40% developed a severe planovalgus deformity. Eight of the 15 lower extremities required further corrective surgery because their resultant deformities limited their ambulation, was painful, or both. The combination of a split tibialis posterior tendon transfer with a distal tibial derotational osteotomy increases the difficulty of balancing the muscle forces across the spastic equinovarus foot, increasing the likelihood that overcorrection and a planovalgus deformity will develop.

Split anterior tibial tendon transfer for recurrent idiopathic clubfoot

Complete anterior tibial tendon transfer for the treatment of the recurrent clubfoot was first described by Garceau.1 Split anterior tibial tendon transfer has been described in the treatment of the spastic equinovarus foot deformity in both the adult and child.2–4 To our knowledge, split tibialis anterior tendon transfer has not been reported before as an isolated treatment of the recurrent idiopathic clubfoot. A split tendon transfer is thought to have a lower risk of over-correction, although this has never been proven in comparative studies. We report our results using a split tendon transfer for the treatment of the recurrent clubfoot. We assess outcome clinically, pedobarographically and ultimately whether the patient required further surgery.

Insertion site for intramedullary tibial nails, and its relationship to anterior knee pain

Recent work has suggested that a patella tendon splitting approach for insertion of intramedullary tibial nails is associated with an increased incidence of anterior knee pain. We looked at 47 patients with 48 tibial fractures stabilised with intramedullary nails. Four nails were unreamed, the rest reamed. Thirty-five fractures were closed, eight Gustillo type 1, three type 2 and two type 3. Information about insertion approach and knee pain was available for 38 patients. Fifty percent had anterior knee pain, 22 had a medial approach performed, 12 had pain, 16 had a patella tendon splitting approach, seven had pain (NS, χ2=0.43). Suitable X-rays were available to allow measurement of patella tendon shortening in 30 patients (patella included on X-ray view). This demonstrated patella tendon shortening of 2.8% in the pain group (n=14); 3.4% in the no pain group (n=16); 3.3% in the split group (n=10); and 3.5% in the medial approach group (n=17, information on surgical approach not available for three patients). The range of shortening for all patients did not exceed 10%. The literature suggests that patella tendon shortening can occur with excessive dissection required for a medial approach at this area of the knee. We agree with recent comments that a controlled trial is required to evaluate this problem further.

Patellar tendon split or parapatellar approach for tibial nailing? Does it affect the patellar height?

We retrospectively studied 18 patients who had intramedullary nailing of the tibia. In nine patients the medial parapatellar approach was used and in the other nine the patellar tendon was split. We found that those patients in whom the patellar tendon was split had significant lowering of the patella compared with the normal knee ( P<0.002, Student's t-test). Those patients who had a medial parapatellar approach to the tibia had no significant lowering of the patella as compared with the other normal knee. It is likely that the patellar tendon splitting approach to the tibia causes the tendon to adhere to the upper tibia causing patella infera.

Peroneus Brevis Tendon Tears: Pathophysiology, Surgical Reconstruction, and Clinical Results

Chronic peroneus brevis tendon tears are frequently overlooked or misdiagnosed. They are a more common problem than previously noted. Twenty patients were reviewed in the largest clinical series of its kind. The most reliable diagnostic sign was persistent swelling along the peroneal tendon sheath. The pathophysiologic mechanism is subclinical, or overt, subluxation of the tendon over the posterolateral edge of the fibula. This produces multiple longitudinal splits. Treatment is primarily surgical and must address both the split tendon and the subluxation that caused it. A new classification that guides surgical treatment is proposed. Debridement and repair are recommended for grade 1 tendons, which have damage to less than 50% of the cross-sectional area. Excision of the damaged segment and tenodesis to the peroneus longus are recommended for grade 2 tendons, which have destruction of greater than 50% of the cross-sectional area. Both methods must be augmented by stabilization of the etiologic subluxation. The average postoperative AOFAS score was 85. Return to maximum function is prolonged, but good-to-excellent results were found in the majority of patients.

Biomechanical study of tibialis anterior tendon transfer.

The tibialis anterior tendon transfer has been used in the treatment of recurrent congenital clubfoot and paralytic equinovarus foot deformities in cerebral palsy. This study attempts to determine the optimal site of tibialis anterior tendon insertion for ankle and foot motion and to compare the split and whole tendon transfer. Ten fresh normal anatomic leg specimens were used. The lateral half of the tibialis anterior tendon was detached from its insertion, passed beneath the extensor retinaculum, and anchored to the appropriate tarsal bone by a barbed staple. Tension was applied, and ankle and foot motions were measured. The experiment was done by anchoring the tendon to the tarsal bones along the axis of the second metatarsal and serially through to the axis of the fifth' metatarsal. The entire experiment was repeated using the whole tibialis anterior tendon. For split tendon transfer, insertion onto the fourth metatarsal axis was the most effective route; it produced maximal dorsiflexion with minimal supination and pronation. For whole tendon transfer, the ideal site of insertion was along the third metatarsal axis. However, the difference between the average maximum dorsiflexion achieved by the split tendon transfer and that of total tendon transfer is not statistically significant.

MR features of longitudinal tears of the peroneus brevis tendon.

Our objective is to describe the characteristic MR imaging features of longitudinal tears of the peroneus brevis tendon and to describe pathologic conditions and normal variants that are associated with these tears which may require surgical intervention at the time of primary tendon repair. We retrospectively reviewed 10 MR images of asymptomatic volunteers and 31 MR images of 27 patients with evidence of longitudinal splits of the peroneus brevis tendon. Seven of these cases were surgically proven. In addition, we assessed five pathologic conditions and normal variants: lateral collateral ligamentous tears; injuries to the superior peroneal retinaculum; low-lying muscle belly of the peroneus brevis tendon; peroneus quartus muscle; and convex, flat, or irregular retromalleolar groove. In the patient's group, we saw longitudinal splits as clefts and an irregularity of the contour of the peroneus brevis tendon with (71%) and without (29%) signal changes on proton density-weighted and T2-weighted MR imaging sequences. Divisions of the split tendon assumed a characteristic C-shaped configuration that partly enveloped the peroneus longus tendon. Fifteen cases revealed other pathologic conditions and normal variants known to be associated with or to predispose to tears of the peroneus brevis tendon. These include ankle ligamentous tears (n = 3); abnormal superior peroneal retinaculum (n = 4); low-lying muscle belly of the peroneus brevis tendon (n = 1); peroneus quartus muscle (n = 2); and convex, flat, or irregular retromalleolar groove (n = 15). MR imaging revealed tears in all patients with surgical proof (n = 7). MR imaging is a useful technique for revealing longitudinal tears of the peroneus brevis tendon as well as showing anatomic and pathologic factors associated with or predisposed to tears.

Traumatic peroneal tendon instability.

To investigate the causes of, pathologic changes associated with, and treatment results after traumatic peroneal tendon subluxation or dislocation, we reviewed 11 cases in 10 patients at a mean followup of 29 months. We also describe a technique of superior peroneal retinacular repair combined with fibular rotational osteotomy. Excellent clinical and functional results were achieved in 9 of the 11 cases, enabling the patients to return to previous competitive sports by 3 months. There was one persisting subluxation that required further surgery. Another ankle, with chronic sepsis from previous surgery and documented degeneration of the ankle joint, had a recurrence of the infection and sequestration of the osteotomized fragment. The personal tendons, however, remained stabilized by the resultant scar tissue. We conclude that superior peroneal retinacular repair, with or without fibular rotational osteotomy, is a successful technique in treating both acute and recurrent instability of the peroneal tendons. It can be combined with a Bröstrom repair when there is concurrent peroneal tendon and anterolateral ankle instability. Peroneal tenosynovitis and tendon splitting were commonly found at operation, especially in cases of recurrent instability. The degree of pathologic change in the tendon did not affect the clinical result.

Redefining the Anatomy of the Anterior Tibialis Tendon

The observation that, when performing a split anterior tibialis tendon transfer, a twist develops as the distal segment is brought into position on the lateral side of the foot led to our hypothesis that, as a consequence of foot rotation during embryologic development, rotation of the tendon of the anterior tibialis muscle also occurs and can be seen in the adult. Ten unembalmed human lower extremities were examined with regard to the macrostructure of the anterior tibialis tendon. In all 10 specimens, the fibers rotated through 90 degrees from the musculotendinous junction to the insertion on the first cuneiform and metatarsal. The tendon was then split, releasing the first metatarsal insertion in five specimens and the first cuneiform insertion in five. Lateral transfer of the first metatarsal-released group produced a crossing over proximally of the tendon as the fibers came from the medial side of the musculotendinous junction. Lateral transfer of the first cuneiform-released group produced no crossing over proximally as the fibers came from the lateral side of the musculotendinous junction. During a split anterior tibialis tendon transfer, release of the cuneiform insertion will avoid the proximal twisting seen with first metatarsal release and allows for a more direct line of pull of the muscle on the tendon.

Coronal plane lengthening of achilles tendon

Surgical Principles The antero-posteriorly flat Achilles tendon is longitudinally sectioned in a coronal plane. Proximally the longitudinally split tendon is severed posteriorly and distally, the tendon is cut anteriorly. During the manual correction of the pes equinus both parts of the tendon slide against each other leaving a sufficient overlap of the divided surfaces. We published this technique first in 1982 [1].