Relative Motion Splint: Active Motion After Extensor ...

1 SURGICAL TECHNIQUER elative Motion Splint: Active Motion AfterExtensor Tendon Injury and RepairWyndell H. Merritt, MDThe Relative Motion splint was initially developed to facilitate postoperative rehabilitation afterrepair of Extensor tendon injuries at the dorsumof the handand forearm. It has subsequentlybeenused for rehabilitation of sagittal band injuries and After repair of closed attrition Extensor tendonruptures in rheumatoid arthritis. This is much less awkward than other braces and can readily beworn during normal past-time and work activities. This so-called immediate controlled activemotion splinting protocol has also more recently been applied to both operative and nonsurgicalrehabilitation for boutonniere deformity.(J Hand Surg Am. 2014;39(6):1187e1194. Copyright 2014 by the American Society for Surgery of the Hand. All rights reserved.)Key wordsTendon therapy, Extensor tendon, laceration, boutonniere, sagittal TENDON INJURIES HAVE traditionally beentreated by either 4 to 6 weeks immobilization,with possible loss offlexion owing to jointstiffness, or dynamic splinting that may (or may not)

2 Provide passive gliding of the injured tendon but re-quires wearing an awkward recently,early Active short arc Motion is proposed for ex-tensor tendon injuries of thefinger, but this requirescareful monitoring and intensive therapy with activemotion only under therapist supervision during thefirst 3 weeks, and immobilization in a palmar restingsplint followed by a home program that requires acompliant patient to do home Active Motion Motion splinting, also known as imme-diate controlled Active Motion splinting,3encouragesimmediate full Active function of the hand, unre-stricted other than 15 to 20 less extension orflexionof the metacarpophalangeal (MCP) joint, dependingon the injury. We have used this patient-friendlymanagement technique in long Extensor lacerations forover 30 years,4and then more recently for boutonnieredeformity, sagittal band rupture,5and side-to-sidetendon repair After rheumatoid Extensor tendon rup-tures in caput ulnae syndrome, preserving full inter-phalangeal joint Motion and minimizing the need forintensive hand Relative Motion concept is simple.

3 When aninjured tendon is placed in 15 to 20 less relativemotion than adjacent tendons from a shared muscle( Extensor orflexor), it will experience markedly lessforce than adjacent tendons,6regardless of the positionfrom full extension to fullflexion (minus the 15 to20 difference at the MCP joint). With long extensorrepair in zones IV to VII, all extensors function likethe single unit Extensor digitorum communis extensors recover equally well as thecommon extensors when placed in 15 to 20 greaterMCP extension than the adjacent digits (Fig. 1). Thisconcept is also effective in reducing tension acrosssagittal band ruptures and side-to-side tendon transfersin caput ulnae syndrome. We call this therelativemotion Extensor boutonniere deformity, the lumbricals have 4times the excursion of the more powerful interossei,From the Department of Plastic Surgery, University of Virginia, Charlottesville, for publication March 10, 2014; accepted in revised form March 16, author expresses appreciation to Dr.

4 Don Lalonde for use of his video of dramatic repairand splinting in a boutonniere deformity patient whose Extensor hood had been ground benefits in any form have been received or will be received related directly orindirectly to the subject of this author:Wyndell H. Merritt, MD, Department of Plastic Surgery, Uni-versity of Virginia, 7660 E. Parham Road, MOB I, Suite 200, Henrico, VA 23294; 2014 ASSHrPublished by Elsevier, Inc. All rights Techniqueand therefore are the principal extensors of the inter-phalangeal (IP) lumbricals arise from theflexor digitorum profundus tendons that come from asingle motor unit. Therefore, placing the injuredextensor hood digit into 15 to 20 greater MCPflexion Relative to adjacent digits places laxity in thatprofundus tendon, which relaxes that lumbrical fromits downward pull while increasing tension on theextensor hood, encouraging dorsal repositioning,regardless of whether the patient fullyflexes or ex-tends (minus the 15 to 20 MCP extension comparedwith its neighboring digits).

5 We call this arelativemotionflexor is easily demonstrated in thecadaver by creating a large boutonniere deformity andplacing a cotton tip applicator or tongue blade over theproximal phalanx of the operated digit and beneath theadjacent digits, then pulling on the common extensormuscles (seeVideos 1 and 2, available on theJour-nal sWeb site ). It canalso be demonstrated in a patient with an acute closedboutonniere deformity and supple joints (Fig. 2).TECHNIQUELong Extensor repair zones IV to VIIA fter long Extensor tendon repair, a thermoplasticyokefinger splint is constructed, placing the repairedtendon(s) in approximately 15 to 20 greater MCPextension than adjacent digits for 6 weeks, preservingfull IP range of Motion . The wrist is placed inapproximately 20 to 25 extension with a separatesplint for thefirst 3 weeks to avoid passive tension onthe suture line from full composite wrist andfingerflexion (possibly unnecessary; see Pearls ).

6 After 3weeks, the wrist splint is discontinued and only thefinger splint is used for an additional 3 weeks (Fig. 3).Thereafter, fullflexion is usually present or isquickly recovered ( of the opposite handflexionwas present at 6 wk, and of total Active motion5).Full normal work and play activities are encouraged inthe splint (Fig. 4). The compliant patient must under-stand that thefinger splint is worn constantly for theinitial 6-week interval. Therapy goals are to make surethe patient recovers full IP and MCPflexion andextension in the splint and in adjacent digits as soonas possible After repair. Thereafter, only occasionalmonitoring is needed. In our series, an average of 8therapy visits were needed, and return to work averaged18 days. Additional therapy After 6 weeks was unusualin all but those with complex injuries or delayed repairand splinting. The average discharge was at 7 weeksafter et al9demonstrated notably earlierrecovery of Motion and return to 1:Because of the 1-motor system, a Relative Motion extension splint relaxes the repair regardless of the MCP and IP Motion SPLINTJ Hand Surg , June2014 Surgical TechniqueSagittal band rupture acute and chronicPatients with acute sagittal band rupture, less than 2or 3 weeks After injury, can usually centralize thetendon when placed in extension and will experiencepain relief soon After Relative Motion Extensor splinting,even whenflexing in the splint.

7 These patients aresplinted in a similar fashion to long Extensor repairs,without the wrist splint component. Success is evidentFIGURE 2: AAcute boutonniere deformity is easily corrected by simply pushing the proximal phalanx into splint for the littlefinger, with no wrist component for 6 3:Immediate Active Motion After longfinger Extensor repair:Awrist splinted 3 weeks;Bfinger splinted 6 Motion SPLINT1189J Hand Surg , June2014 Surgical Techniqueby encouraging fullfingerflexion in the splint (minus15 to 20 at the MCP joint), which should be pain freewithout tendon subluxations. This splint is then main-tained for 6 weeks (although others recommend 8wk).10 Little or no additional therapy is usually neededonce full Motion in the splint has been techniques to correct chronic sagittal bandrupture usually recommend 8 to 10 weeks of immo-bilization with a variety of surgical procedures , fromdirect repair to various tendon slips from juncturaetendinum, or a strip from the Extensor digitorumcommunis.

8 We prefer to create a tendon graft pulleydirectly into the head of the metacarpal,5done usingpalmaris longus, juncturae tendinum, a strip ofextensor retinaculum, or a strip of Extensor indicisproprius (Fig. 5). All of these have been used suc-cessfully, followed by Relative Motion extensorsplinting for 6 weeks using only thefinger componentand no wrist splint. Full activity and use is encouragedand full recovery offlexion should be expected. It isuseful to perform the surgery with local anesthesia toappreciate the value of the splint (seeVideos 3 and 4,available on theJournal sWeb site ). Although the current author has notdone so, other surgical methods to centralize thetendon should be expected to heal equally well withthis Relative Motion Extensor splint that permits activeuse and protects the repair. This technique has beensuccessful in rheumatoid arthritis patients, although 1developed recurrence After 7 deformity zone IIIC orrection of acute closed boutonniere deformitywhen full passive extension is possible can be demon-strated by simply placing a cotton tip applicator over theproximal phalanx of the injured digit and beneath theproximal phalanges of the adjacent digits; sometimes,simple digital pressure on the proximal phalanx willsuffice.

9 If full proximal interphalangeal (PIP) extensionis possible, simple relativeflexion splinting alone (nowrist component) for 6 weeks should result in preser-vation of full extension andflexion, with functional useduring the splinting interval (Fig. 6). This concept isdemonstrated in cadaver dissection and clinical cases(seeVideos 3 and 4, available on theJournal sWeb ).Open acute boutonniere repair is best accomplishedusing local anesthesia with epinephrine (either lido-caine or bupivacaine), especially in complex woundsto ensure the delicate balance is restored betweenthe intrinsic tendons and the Extensor hood. Onceaccomplished, Motion can be preserved by relativemotionflexor splinting, although early therapymonitoring is usually needed to ensure that the patientfully extends andflexes. The patient can resume usualhand use, and is encouraged to do so within the re-straints of the splint for 6 weeks (Video 4).

10 Chronic boutonniere has been a surgical conun-drum, with poor results reported, especially in olderpatients and those withfixedflexion authors agree that initial nonsurgical efforts toobtain passive PIP extension by serial casting anddynamic splinting are warranted, but this is too oftenfollowed by loss of Active extension and recurrentflexion contractures. It is hard for patients to toleratethe functional impairment of 2 to 3 months of gutter ordynamic Extensor splinting that is often serial casting achieves maximum PIPextension, if it is better than 30 , the author acceptsthis and uses Relative motionflexor splinting full-timefor 3 months. This splint is compatible with Active useof the hand, permitting fullflexion, and patients aretherefore compliant. At the end of 3 months, the de-gree of improved PIP extension has been maintained,with follow-up as long as 3 years, in the author sexperience.