Proximal Interphalangeal Joint Fusion Research Articles

Functional evaluation of optimal index finger proximal interphalangeal joint fusion angle using a simulated joint arthrodesis

This study aims at qualitatively and quantitatively evaluating the effects of simulated index finger proximal interphalangeal (PIP) joint fusion angles on hand kinematic function and performance. Although arthrodesis of the index finger PIP joint is an effective medical procedure that produces a durable, pain-free, and stable joint, it permanently immobilizes the joint. Twenty healthy subjects performed basic functional hand activities with the index finger PIP joint unconstrained (UC) and constrained to selected angles under surveillance of a motion capture system. Our results indicate differences in perceived difficulty, time performance, and the functional ROM of the hand joints when the index finger PIP joint is UC and constrained to 0, 20, and 40 degrees of flexion. The mean total perceived difficulty scores for all 6 tasks were higher for the PIP at 0 degrees than for the UC condition (p < 0.001) and for the PIP at 40 degrees (p = 0.048). The functional ROM presented a smaller total number of hand joints affected by the PIP at 20 degrees (25 in total) than the PIP at 0 (31 in total) and 40 (27 in total) degrees during execution of all 6 tasks tested. Therefore, the decision on the appropriate index finger PIP angle for arthrodesis may be between 20 and 40 degrees, as globally for all 6 tasks tested, 0 degrees exhibited the worst results regarding perceived difficulty, performance time, and number of joints with affected ROM. Selecting the appropriate angle for arthrodesis should consider a more complete set of functional activities.

Effect of a single proximal interphalangeal Joint Fusion of the Index, Middle or Ring Finger on the Grip and Finger Force and Load Distribution in the Hand

Due to the functional coupling of adjacent finger joints and the quadriga effect, arthrodesis of the proximal interphalangeal joint (PIPJ) can be assumed to lead to a different grip pattern resulting in altered force distribution of the hand. Ten patients with isolated arthrodesis of the PIPJ due to posttraumatic osteoarthritis (4×PIPJ II, 4×PIPJ III, 2×PIPJ IV) were assessed 59 (17-121) months postoperatively on average. The angle of arthrodesis was assessed by radiographs. Grip force and load distribution of both hands were measured by manugraphy using 3 differently sized cylinders. Grip force was separately assessed and compared for the whole hand as well as for each of the fingers and each phalanx. Average total grip force of the affected hand compared to the uninjured opposite side was 74% (38-136%) for the small cylinder, 104% (68-180%) for the mid-sized cylinder and 110% (69%-240%) for the large cylinder. Arthrodesis of the PIPJ of the index finger led to a reduction of the grip force (91%) for the small cylinder, but increased grip force for the mid-sized (120%) and large cylinder (139%). Grip force was reduced for all cylinder sizes by arthrodesis of the PIPJ of the middle finger (56%, 88% and 91%). Arthrodesis of the PIPJ of the ring finger resulted in a grip force of 76%, 105% and 91%, respectively, for the different cylinder sizes.The finger force of the affected finger was reduced after arthrodesis of the PIPJ, with the exception of the index finger, which was stronger than the unaffected opposite finger when using the large cylinder. The force of the healthy fingers on the affected side was greater when compared with the same finger on the opposite side, which led to increased grip force for the mid-sized and the large cylinder of the affected hand. A reduction in load distribution was measured mostly for the middle phalanx but also for the distal phalanx of the operated-on finger. Arthrodesis of the PIPJ almost always led to force reduction in the middle and distal phalanx of the affected finger. However, the total grip force of the hand was compensated by a higher force of the adjacent healthy fingers. In many cases, total grip force was even higher on the affected side. However, arthrodesis of the PIPJ resulted in a noticeable force reduction when smaller objects were gripped.

Flexor tenotomy for mallet toe with penetration of the middle phalanx head by dual-component intramedullary implant following proximal interphalangeal arthrodesis.

IntroductionThere is a risk of mallet toe following proximal interphalangeal (PIP) joint fusion for hammertoe. Here we describe a rare case of penetration of the dorsal aspect of the middle phalanx head by the distal portion of a dual-component intramedullary implant during progression of mallet toe that was treated with flexor tenotomy.Presentation of caseA 59-year-old man underwent uneventful arthrodesis of the third PIP using a dual-component intramedullary implant and presented 6 months later with progressive mallet toe and swelling, pain, and ulceration over the distal interphalangeal joint of the third toe. Imaging showed that the distal portion of the implant had penetrated the dorsal aspect of the middle phalanx head. A longitudinal incision was made over the dorsum of the middle and proximal phalanges of the third toe and the implant was removed. A plantar incision was made at the metatarsophalangeal joint and the flexor tendon was cut to correct the mallet toe deformity. One year later, correction was satisfactory with an acceptable functional outcome and good pain relief.DiscussionWe successfully treated a man with penetration of the dorsal border of the middle phalanx head in the third toe by the distal portion of a dual-component intramedullary implant as a result of mallet toe that developed following PIP arthrodesis, by removing the implant and performing flexor tenotomy.ConclusionAddition of flexor tenotomy should be considered when performing PIP arthrodesis in a patient with risk factors for severe mallet toe.

Hammertoe Correction with Wire Fixation of Varying Length

Category:Midfoot/Forefoot; Lesser ToesIntroduction/Purpose:Hammertoe deformities are commonly encountered and frequently require surgical intervention for pain relief and shoewear accommodation. Various techniques exist for surgical management, but proximal interphalangeal (PIP) joint fusion with Kirschner (K) -wire fixation remains an inexpensive, popular treatment. The decision to place a K wire that spans the metatarsophalangeal (MTP) joint versus only fixating the digit through the proximal phalanx is entirely dependent on provider preference and situational context. This study was performed to evaluate the effect of length of wire fixation on clinical outcomes after hammertoe reconstruction.Methods:A retrospective review of all hammertoe reconstructions by a single fellowship trained foot and ankle surgeon from 2017-2021 was performed. Hammertoe reconstructions involved PIP arthrodesis with double wire fixation and other supplemental balancing procedures as indicated. Pins were routinely removed at between 5-6 weeks and protected heel weightbearing was generally advised. Wire length was chosen at the discretion of the surgeon intraoperatively. Patients were excluded if no radiographic follow-up was available after pin removal. Patient outcomes were evaluated with radiographs and clinic notes to assess pin length, pin complications/breakage, return to the OR, MTP congruency, and PIP union rate. A logistic regression was performed to determine the odds ratio for digit congruency and non-union status.Results:88 toes (45 patients) underwent hammertoe reconstruction with K wire fixation. Of these toes, 47 had wires that spanned the MTP and 41 that did not. There were 65 congruent MTP joints and 23 incongruent joints. 16 of the incongruent joints were pinned across the MTP while 31 in the congruent group were pinned. One toe in the MTP group required return to the OR for removal of a broken wire, compared to zero in the phalanx group (p=1.0). No pins broke in the phalanx group, compared to 3 in the MTP group (p=0.25). One toe in the proximal phalanx group had their pins pull out early but no return to the OR was needed. There were 26 (63.4%) PIP radiographic nonunions, compared to 21 (44.7%) in the MTP group (p=0.12).Conclusion:Wire failure was a rare occurrence in either group. Breakage only occurred in the MTP group, but only required one surgical intervention for removal. Pinning the MTP may allow for improved deformity correction and increased stability of the hammertoe reconstruction. Pin breakage can occur, but it may be of little clinical significance. The increased stability and control of MTP correction may be worth the potential risk of pin breakage. Pin breakage may be avoided potentially by using thicker wires, earlier removal, and protected weightbearing.

Novel NOG (p.P42S) mutation causes proximal symphalangism in a four-generation Chinese family

BackgroundProximal symphalangism (SYM1; OMIM 185800), also called Cushing’s symphalangism, is an infrequent autosomal dominant disease. An SYM1 patient typically features variable fusion of proximal interphalangeal joints in the hands and feet.MethodsWe recruited a four-generation Chinese non-consanguineous family with SYM1. We examined their hands and feet using X-rays to confirm fusion of proximal interphalangeal joints. We evaluated their audiology using standard audiometric procedures and equipment. Then, we identified genetic variants using whole exome sequencing and validated mutations using Sanger sequencing. Mutation pathogenicity was analyzed with bioinformatics.ResultsRadiographs revealed proximal-joint fusion of fingers and toes in the patients. Two elderly individuals (II:1 and II:4) exhibited slight hearing loss. Additionally, we detected a novel heterozygous missense mutation in exon 1 of NOG (NM_005450) c.124C > T, p.(Pro42Ser) in all patients. This c.124C > T mutation is highly conserved across multiple species and the p.(Pro42Ser) variation is potentially highly pathogenic.ConclusionOur results suggest that heterozygous c.124C > T, p.(Pro42Ser) in NOG is a novel mutation that causes human SYM1 phenotype.

Identification of a Novel NOG Missense Mutation in a Chinese Family With Symphalangism and Tarsal Coalitions.

BackgroundProximal symphalangism (SYM1) is a rare genetic bone disorder characterized by the fusion of proximal interphalangeal joints in the hands and feet. Genetic studies have identified two genes underlying SYM1 as the noggin (NOG) and the growth differentiation factor 5 (GDF5).Case ReportIn the present report, a 43-year-old gravida at 11 weeks of gestation was referred for evaluation of abnormal fusions of the joints. In the initial diagnosis, physical examination was undertaken. However, traditional radiological examination was not applied due to the need to protect the fetus, making diagnosis results inefficient to determine the exact disease affecting the proband. To acquire alternative clinical evidences, we conducted radiological examinations on two other affected family members. The radiological examination revealed that they carried the symphalangism accompanied with tarsal coalition, a very rare manifestation of SYM1. A combination of whole exome sequencing (WES) and Sanger sequencing revealed a novel heterozygous missense mutation (c.163G > T; p.Asp55Tyr) in the NOG gene, which could be associated with the observed pathogenic SYM1 in the studied family. The p.Asp55Tyr mutation co-segregated with SYM1 through the affected and unaffected family members. In silico structural modeling of the p.Asp55Tyr mutation showed that it abolishes the interaction with the Arg167 residue and causes a change in the electrostatic potential profile of the type II binding site of the noggin protein.ConclusionOur findings indicate that the genetic test based on WES can be useful in diagnosing SYM1 patients, with particular advantages in preventing the fetus from contacting harmful X-ray through the traditional radiography. The novel pathogenic mutation identified would further expand our understanding of the mutation spectrum of NOG in association with SYM1 disease and provide a guidance on how to determine whether the fetus is affected by SYM1 through the prenatal diagnosis.

Comparative Study of Intramedullary Hammertoe Fixation.

Temporary Kirschner wire fixation (K-wire) is a widely used, low-cost fixation method for the correction of hammertoe deformity. Reported complications associated with K-wires prompted the development of new implants over the past decade. However, there is a lack of literature on comparative studies analyzing functional outcomes using validated questionnaires. The purpose of this study was to analyze functional outcomes in patients who had undergone proximal interphalangeal joint fusion using 2 types of intramedullary implant, the Smart Toe and the TenFuse, and to compare them with the outcomes in patients treated with standard K-wire fixation. A retrospective review of operative hammertoe correction by a single surgeon was performed in 96 patients followed for more than 12 months. Functional outcome was assessed using the Foot Function Index (FFI), the Short Form 36 (SF-36), and the 10-point visual analog scale (VAS) validated questionnaires. Complications and fusion rates were also evaluated. Several patients in the study underwent corrections in different toes; thus, a total of 186 toes were included in the study. From these, 65 toes (34.9%) were treated with K-wire fixation, 94 (50.5%) with Smart Toe titanium implant, and 27 (14.5%) with TenFuse allograft implant. No statistically significant differences in functional outcome and incidence of complications were observed among the 3 fixation groups, although the 2 intramedullary implants were associated with greater fusion rates and patient satisfaction. Breakage of the Smart Toe implant was significantly higher than that of the other fixations, with 10.6% of implants breaking within the first year postoperatively. SF-36 and VAS scores decreased 12 months after surgery for the 3 types of fixation, with no statistically significant differences observed. The use of Smart Toe and TenFuse implants provided operative outcomes comparable to those obtained using a K-wire fixation and slightly better patient satisfaction. Our results suggest that utilization of these implants for hammertoe correction was a reasonable choice that provided good alignment, pain reduction, and improved function at final follow-up. However, they are more expensive than K-wires. For this reason, in-depth cost-benefit studies would be required to justify their use as a standard treatment. Level III, comparative series.

Corrective procedures and indications for cavovarus foot deformities in children and adolescents

Cavovarus deformities in children and adolescents require sound considerations concerning the timing for corrective surgery. Progression can be recognized best by repeated pedographic examination with evaluation of the typical features of cavovarus deformity. Surgical correction consists of acombination of soft tissue release, bony realignment, and restoration of muscle balance. In most cases plantar or medioplantar soft tissue release should be considered, whereas calf muscle lengthening is rarely indicated. Typical joint-sparing bone procedures are elevating osteotomies at the medial tarsometatarsal ray and realigning calcaneal osteotomies. Advanced cases require navicular-cuneiforme arthrodesis for correction of severe cavus component, hindfoot fusion at the Chopart line, or Lambrinudi triple fusion. Supramalleolar rotational osteotomy should be considered in severe cases. Peroneal dysfunction is addressed by peroneus longus to brevis transfer, posterior tibial tendon transfer compensates for severe extensor weakness to acertain degree, claw toes can be rebalanced by flexor or extensor tendon transfer, often in combination with proximal interphalangeal joint fusion. Surgical treatment should take into account the components of deformity, muscular function, progression and the underlying disease of the individual case. Further deterioration can be prevented by adequate surgery in the young patient. However, repeated surgical interventions may be necessary later in this patient group.

Sustainability of Forefoot Reconstruction for the Rheumatoid Foot

Ninety percent of patients with rheumatoid arthritis will display foot and ankle pathologic features, including hallux valgus, lesser metatarsophalangeal (MTP) joint subluxation/dislocation, and hammertoe deformity. Recently, a trend has ensued toward joint preservation with distal metatarsal osteotomies and various bunion corrective procedures. However, the reference standard remains first MTP joint fusion, lesser metatarsal head resection, and lesser proximal interphalangeal joint fusion. The present retrospective study followed the results of 4 different surgeons who had performed the reference standard rheumatoid forefoot reconstruction from August 2008 to August 2012 on patients with rheumatoid arthritis. Radiographic and statistical analysis of the data from 20 patients determined an overall first MTP joint fusion rate of 90%, often occurring by 108 (range 64 to 202) days postoperatively. Radiographic nonunion occurred in 2 of the 20 patients (10%), although both were asymptomatic, with no revision necessary. Lesser digit deformity revision occurred in 1 patient (5%), and mild to moderate infection developed in 4 patients (20%). The radiographic and clinical follow-up period was 12 months. Our study found that this technique provides exceptional radiographic improvement, an acceptable time to fusion, a low reoperation rate, and minimal complications. In addition, correction of the deformity was maintained at 1 year postoperatively. In conclusion, first MTP joint fusion with lesser metatarsal head resection should remain the reference standard for surgical intervention of the rheumatoid foot.

Two-Pin Fixation of Proximal Interphalangeal Joint Fusion for Hammertoe Correction

Single-pin external Kirschner wire (K-wire) fixation has traditionally been a mainstay in proximal interphalangeal joint fusion for central hammertoe repair. Concerns over cosmesis, inconvenience, pin tract infection, hardware failure, nonunion, and early hardware removal have led to the development of implantable internal fixation devices. Although numerous implantable devices are now available and represent viable options for hammertoe repair, they are costly and often pose a challenge in the event removal becomes necessary. An alternative fixation option not typically used is a 2-pin K-wire fixation technique. The perceived advantage of obtaining 2 points of fixation compared with 1 across the fusion site is improved stability against the rotational and bending forces, thus decreasing the potential for pin-related complications. A retrospective assessment of 91 consecutive hammertoe repairs consisting of proximal interphalangeal joint fusion with 2-pin fixation in 60 patients was performed. The K-wires were removed at 6 weeks postoperatively, and the overall postoperative follow-up duration was 28.56 (range 1.40 to 86.83) months. Of the 91 digits, 89 (98%) did not encounter a complication postoperatively and 2 (2.20%) had sustained loosened or broken hardware. No postoperative infection was encountered. The low incidence of complications observed supports the 2-pin K-wire fixation technique as a low-cost and viable construct for proximal interphalangeal joint fusion hammertoe repair.

Lesser Toe PIP Joint Resection Versus PIP Joint Fusion: A Randomized Clinical Trial.

It is unclear whether proximal interphalangeal joint (PIPJ) resection or fusion leads to superior clinical outcome in patients undergoing hammertoe surgery. The purpose of this study was to prospectively evaluate a series of patients undergoing this surgery. Patients with one or more toes with rigid PIP flexion deformity were prospectively enrolled. These patients were randomly assigned to undergo either PIPJ resection or PIPJ fusion. In addition to the PIPJ procedure, a metatarsophalangeal joint (MTPJ) release was performed if deemed necessary. Follow-up was up to 1 year postoperatively. Twenty-six patients (39 toes) were included in the PIPJ resection group and 29 (50 toes) in the PIPJ fusion group. Thirty-four underwent an MTPJ release. No significant difference in foot outcome scores (American Orthopaedic Foot & Ankle Society scale, the Foot Function Index, and visual analog scale pain) could be detected after 1-year follow-up. A statistically significant difference was found regarding the toe alignment in the sagittal plane in favor of PIPJ fusion. Our randomized controlled study did not show any clinical outcome difference between PIPJ fusion and PIPJ resection. Both procedures resulted in good to excellent outcome in pain and activity scores. Level II, lesser quality RCT or prospective comparative study.

Salvage of a Lesser Toe Osteomyelitis when Complicated by a Broken Screw: A Case Study

Orthopedic screw removal has proven itself to be a challenge. Access to a Screw Removal Set (TM Synthes) is essential. But what options are available when it cannot remove a broken screw in a lesser toe on a background of osteomyelitis of a lesser toe? A young healthy patient had undergone a 2nd and 3rd toe proximal interphalangeal joint (PIPJ) and distal interphalangeal joint (DIPJ) fusion using a cannulated dual threaded compression screw in 2006. She had had a successful fusion but eight years later, she developed osteomyelitis in the 2nd toe. An attempt was made to manage this conservatively with antibiotic therapy but a further flair up occurred following treatment. At surgery, the screw head broke while trying to remove it leaving just the smooth shaft of the screw, deep within the proximal phalanx. The Screw Removal Set was not useful and it was removed by making a gutter dorsally.

Biomechanical Evaluation of 5 Fixation Devices for Proximal Interphalangeal Joint Arthrodesis

To determine in a cadaver model which, among 5 fixation methods for proximal interphalangeal (PIP) joint arthrodesis, has the greatest stiffness. Thirty-five cadaver digits were randomly assigned to 1 of 5 fixation groups: oblique K-wire with coronal intraosseous wiring, tension-band wire (TBW), dorsal plate, intramedullary linked screw (IMS), and 90/90 wiring (90/90W). Testing was done by applying bending moments to the PIP joint in the sagittal and frontal planes. The force/displacement curves were used to estimate the stiffness of each construct. Ultimate strength was determined by loading to failure in extension. The IMS had significantly higher stiffness than all wiring constructs in all planes of motion and significantly greater stiffness in extension than the dorsal plate. The IMS stiffness exceeded 10 N/mm across all bending directions and showed an ultimate strength of 21 N. The plate demonstrated higher stiffness in radial bending than the oblique K-wire with coronal intraosseous wiring and TBW. There were no differences in stiffness between the IMS and plate in all modes of testing except extension. Load-to-failure testing of the devices showed the IMS device to be significantly stronger than the TBW, 90/90W, and plating constructs. The IMS resisted larger bending moments than all wiring constructs and showed the greatest ultimate strength when compared with 3 of the tested arthrodesis techniques. The plate was significantly better than 2 of the wiring constructs, but only in radial bending. No differences were found between the, TBW, and 90/90W when compared with each other. The stiffness necessary for a successful PIP joint fusion has not been quantified, but according to this study, the IMS was the most favorable biomechanical construct for initial stability.

Flexor Digitorum Brevis Transfer for Floating Toe Prevention after Weil Osteotomy

A floating toe deformity occurs in many patients who undergo Weil osteotomies. It is likely caused by the failure of the windlass mechanism in shortening the metatarsal. For patients who require a proximal interphalangeal (PIP) joint arthroplasty or fusion in addition to a Weil osteotomy, the transfer of the flexor digitorum brevis (FDB) tendon to the PIP joint might restore the windlass mechanism and decrease the incidence of floating toes. Fourteen cadaveric foot specimens were examined to determine the effects of changing metatarsal length as well as tensioning the FDB tendon on the angle of the metatarsophalangeal (MTP) joint as a measure of a floating toe. Shortening and lengthening the second metatarsal resulted in a significant change in MTP angle (P = .03 and .02, respectively), though there was no clear relationship found between the amount of change in metatarsal length and the change in MTP angle. Transferring the FDB to a PIP arthroplasty site plantarflexed the MTP joint and corrected floating toes; the change in angle was significant compared with the control and shortening groups (P = .0001 and .002, respectively). This study supports the theory that change in length of the metatarsal, possibly via the windlass mechanism, plays a role in the pathophysiology of the floating toe deformity. Tensioning and transferring the FDB tendon into the PIP joint helped prevent the floating toe deformity in this cadaveric model. Continued research in this subject will help to refine methods of prevention and correction of the floating toe deformity.

StayFuse for Proximal Interphalangeal Joint Fusion

Proximal interphalangeal (PIP) joint fusion is a commonly performed procedure for lesser-toe deformities. There are various techniques described to accomplish it. We report the results of PIP joint fusion carried out with an intramedullary fusion device in 150 consecutive toes. The aim of our study was to evaluate the outcomes of PIP joint fusion with this technique. A total of 150 toes in 140 consecutive patients who underwent PIP joint fusions of the lesser toes with a StayFuse implant were included in our study. The mean age of the patients was 69.5 years, and the mean follow-up was 18 months. Clinical, radiologic, and subjective evaluations as well as preoperative and postoperative American Orthopaedic Foot and Ankle Society (AOFAS) scores were carried out. Of the PIP joints, 95.3% were clinically asymptomatic, but the radiologic fusion was 73%. The mean preoperative AOFAS score improved from 22.9 to 81.6 at follow-up. There were implant-related complications in 8 toes. Ninety-five percent of the patients were satisfied with the procedure, and 3.3% of the patients needed revision surgery. This technique maintained PIP joint alignment and provided rotational and angular stability with high patient satisfaction and low complication and reoperation rates. We conclude that this is a reproducible technique and an alternative for PIP joint fusions. Level IV, retrospective case series.

Management of severe Dupuytren’s contracture of the proximal interphalangeal joint with use of a central slip facilitation device

Thirty-eight fingers in 27 patients with Dupuytren's contracture of the proximal interphalangeal joint (PIPJ) in excess of 70° were treated using a staged technique. The first stage involved applying a mini external fixator across the PIPJ for continuous extension over 6 weeks with intensive hand therapy to maintain mobility of the joint and help correct the deformity. Twice weekly during hand therapy sessions the tension of the elastic band across the mini ex-fix was increased, allowing that full active flexion of the PIPJ against the elastic band could still be achieved. The second stage, 4 weeks after the external fixator was applied, involved an open palm technique of fasciectomy for the contracted cords restricting metacarpophalangeal joint movement and dermofasciectomy with full-thickness skin grafting over the proximal phalanx for bands restricting PIPJ movement. The external fixator was used to maintain active extension force until the graft healed. It was generally removed in the outpatient clinic under ring block 2 weeks after the second stage procedure. The patients were followed for a mean of 20.6 (6-48) months. The mean preoperative PIPJ deformity improved from 75° to 37° postoperatively. Overall, 69% of results were rated as good to excellent. Only one patient reported any on-going functional problems. There were eight cases of pin site infections and one case each of loose pins, osteoarthritics at the PIPJ, reflex sympathetic dystrophy, and disease recurrence needing PIPJ fusion. We conclude that our simple staged procedure is a valid alternative in the management of severe Dupuytren's PIPJ contracture.

Influence of Index Finger Proximal Interphalangeal Joint Arthrodesis on Precision Pinch Kinematics

To evaluate the impact of proximal interphalangeal (PIP) joint arthrodesis on the kinematics of precision pinch. Eleven healthy subjects performed index finger-thumb pinch motions under 4 conditions: unrestricted thumb and index finger (CONTROL) and fusion of the PIP joint of the index finger in flexion of 30° (PIP30), 40° (PIP40), and 50° (PIP50). Fusion was simulated with metallic splints. Kinematics of the thumb and index finger were recorded with a motion capture system. Proximal interphalangeal joint fusion at 30°, 40°, and 50° restricted maximal pinch span between the thumb tip and index finger tip by 6%, 10%, and 14%, respectively. At the time of pulp contact, PIP fusion led to an increase in index metacarpophalangeal joint flexion angle for the PIP30 condition and an increase in variability of thumb tip location for the PIP50 condition. Furthermore, the dynamic coordination between joint angles throughout the movement was affected by PIP fusion. This study reports impairment in the kinematics of precision pinch associated with index finger PIP joint fusion. A PIP joint fusion at 40° to 50° leads to a more natural precision pinch posture, but it restricts the aperture and reduces pinch precision.

Advantages and Drawbacks of Proximal Interphalangeal Joint Fusion Versus Flexor Tendon Transfer in the Correction of Hammer and Claw Toe Deformity. A Finite-Element Study

Correction of claw or hammer toe deformity can be achieved using various techniques, including proximal interphalangeal joint arthrodesis (PIPJA), flexor digitorum longus tendon transfer (FDLT), and flexor digitorum brevis transfer. PIPJA is the oldest technique, but is associated with significant complications (infection, fracture, delayed union, and nonunion). FDLT eliminates the deformity, but leads to loss of stability during gait. Flexor digitorum brevis tendon transfer (FDBT) seems to be the best surgical alternative, but it is a recent technique with still limited results. In this work, these three techniques have been analyzed by means of the finite-element method and a comparative analysis was done with the aim of extracting advantages and drawbacks. The results show that the best technique for reducing dorsal displacement of the proximal phalanx is PIPJA (2.28 mm versus 2.73 mm for FDLT, and 3.31 mm for FDBT). However, the best technique for reducing stresses on phalanges is FDLT or FDBT (a reduction of approximately 35% regarding the pathologic case versus the increase of 7% for the PIPJA in tensile stresses, and a reduction of approximately 40% versus 25% for the PIPJA in compression stresses). Moreover, the distribution of stresses in the entire phalanx is different for the PIPJA case. These facts could cause problems for patients, in particular, those with pain in the surgical toe.

The two-pin arthrodesis technique for proximal interphalangeal joint fusion of the lesser toes

Arthrodesis of the proximal interphalangeal (PIP) joints of the lesser toes is a commonly performed procedure for correction of the claw toe and hammer toe deformity. Multiple techniques of fixation have been described to achieve a solid fusion with variable fusion rates (Coughlin and Polk in Operative repair of the fixed hammertoe deformity. Foot Ankle Int 21(2):94–104, 2000). The standard technique for many years uses a single intramedullary K-wire (Baig and Geary in Fusion rate and patient satisfaction in proximal interphalangeal joint fusion of the minor toes using Kirschner wire fixation. The Foot 6:120–121, 1996 ). We present our technique of fusing the PIP joint with two fine K-wires, used to prevent rotational displacement and ensure sound arthrodesis. Our series of 36 fusions in 25 patients were assessed independently using the American College of foot and ankle surgeons score (ACFAS) and the Foot Function Scale (FFS). A fusion rate of 97% was achieved with 89% of patients were satisfied with the appearance of their toes. There was a significant reduction in pain levels with 90% of patients reporting no pain with normal activities. We believe our simple improvement to the single wire technique results in superior outcomes.

The Role of Toe Flexor-to-Extensor Transfer in Correcting Metatarsophalangeal Joint Instability of the Second Toe

The purpose of the study was to evaluate the outcome of flexor digitorum longus (FDL) transfer to the dorsum and to identify a possible continued role for this transfer in conjunction with additional surgeries for second metatarsophalangeal joint (MTPJ) instability. We carried out a retrospective analysis on patients with second MTPJ instability for which the FDL transfer was done as the primary procedure between 1996 and 2001. The patients were examined for functional status, residual pain, and satisfaction. A total of 64 feet (59 patients) were evaluated, with an average followup period of 45.2 (16 to 82) months. A cross-over second toe deformity was present in 56 feet (87%) with a stage II deformity being the most common (18 feet). There also were seven feet with vertical subluxation. An additional second metatarsal Weil osteotomy was done in 29 feet (45%), a proximal interphalangeal (PIP) joint resection arthroplasty in 22 feet, and a PIP joint fusion in nine feet. At final followup of the 59 feet that were physically examined, 22 (37%) had residual second MTPJ dorsiflexion contracture and 16 feet had persistent medial deviation. The second toe was stable to stress manipulation in 46 feet (78%). The mean toe pulp to ground distance on standing was 3 mm, and strong toe grasp was possible in 45 feet. There were 20 complications in 64 feet. Twenty-five patients (29 feet) were very satisfied, 15 satisfied with minor reservations, six with major reservation, and 14 patients were unhappy with the outcome. The American Orthopaedic Foot and Ankle Society functional score was on average 82 points (47 to 100) at final followup. Although the function of the second toe improved in most patients as a result of pain relief, a substantial number of the patients in this study remained dissatisfied because of residual stiffness of the toe. The flexor tendon transfer remains an important procedure in correction of second toe instability but must be used with a full understanding of potential complications and patient dissatisfaction.