The impact of simulated distal interphalangeal joint fusion on grip strength

A Functional Angle of Up to 35° at the Distal Interphalangeal Joint Can Be Achieved with Headless Compression Screw Fusion

BACKGROUND

Arthrodesis of the distal interphalangeal (DIP) joint reliably improves symptomatic arthritis. A range of successful surgical techniques including tension band wiring, plate fixation and headless compression screws have been described and produce stable painless unions. For best functional outcome, the fusion angle should be between 10 and 61 degrees. In the past, it has been difficult to achieve more than 10 degrees of flexion with a headless compression screw. Higher fusion angles have been reported using tension band wiring techniques. However, metalwork prominence is a common problem and may require revision surgery to rectify this. Headless compression screws are reported to cause iatrogenic fractures due to the size of the screw relative to the small diameter of the phalanx. This case series achieves an angle of up to 35 degrees with a good functional outcome.

METHODS

Open fusion of the DIP joint with a headless cannulated compression screw, of 2.2 mm in diameter, was undertaken in fifteen digits. Patients received standard departmental follow up to radiographic union. Patients self-reported function using the Michigan Hand Questionnaire post operatively. The fusion angles achieved were assessed on postoperative radiographs.

RESULTS

All patients went on to a stable union without any patients requiring revision surgery as a result of fracture or protrusion of metalwork. Complications were observed in two patients which included one superficial infection (n = 1) and a discomfort requiring removal of metalwork (n = 1). Functional scores measured post operatively showed favourable outcomes.

CONCLUSIONS

In this series, successful fusions of the DIP joints, at an angle up to 35 degrees were achieved using small diameter headless compression screws, which provided benefits including early mobilization and favourable functional outcome scores.

Effect of immobilization of the distal interphalangeal joint of fingers on grip strength

Arthrodesis of the distal interphalangeal joint of the finger is an effective salvage treatment for end-stage arthropathy of the joint. This study aimed to evaluate the effect of simulated fusion of individual distal interphalangeal joints on the overall grip strength of the hand. Custom moulded thermoplastic splints were used to simulate fusion by immobilizing the index, middle, ring and little fingers' distal interphalangeal joints in turn in both hands of 56 healthy participants. Testing was performed with no immobilization and after immobilization of each of the individual digits. Grip strengths reduced significantly following immobilization of the distal interphalangeal joint. The degree of reduction became progressively more pronounced from the index to the little fingers (12%, 18%, 24% and 25%, respectively) and was similar for the dominant and non-dominant hands. This information may have clinical application when counselling patients regarding fusion of the distal interphalangeal joint of the fingers.

The Effect of Simulated Total Distal Interphalangeal Joint Stiffness on Grip Strength

Purpose

Production of a functional grip pattern requires the concerted action of numerous structures within the hand. This study quantifies the effect of total distal interphalangeal joint (DIPJ) stiffness to grip strength.

Methods

Fifty (25 men, 25 women, 100 hands) individuals with a mean age of 38 years (range: 17-69 years) were recruited. Exclusion criteria included history of previous upper limb injury, neuropathies, or systemic disease. Custom thermoplastic orthoses were used to splint participants' DIPJ in full extension simulating stiffness. Grip strength before and after splinting was measured using a calibrated Jamar dynamometer. Data were analyzed using paired and independent sample t tests and 2 × 2 repeated-measures analysis of variance with hand dominance and configuration (splinted or unsplinted) as within-subject factors.

Results

Restriction of DIPJ flexion led to a 20% decrease in grip strength (P < .001). There was no significant difference in this decrease between dominant and non-dominant hands. Univariate analysis did not demonstrate any interaction between hand dominance and testing configuration. Post hoc analysis revealed no statistical difference in baseline grip strength between the dominant and non-dominant hands. Furthermore, men had significantly stronger grip strength than women in all configurations (P < .001).

Conclusions

Flexion at the DIPJ contributes significantly to grip strength, and stiffness at this joint greatly limits functional capabilities of the hand. This necessitates the need for targeted rehabilitation in DIPJ injuries to minimize adverse effects on grip strength.

Arthrodesis of Little Finger Distal Interphalangeal Joint in Flexion to Regain Sporting Ability

BACKGROUND

Finger injuries are common in the sport of hurling. Injury to the little finger distal interphalangeal joint (DIPJ) often occurs when a high dropping ball impacts on the outstretched finger. The little finger contributes to approximately 15% of grip strength. Injury therefore results in reduced grip strength and may impair the ability of players to grip or catch a ball.

METHODS

Six elite hurlers with post-traumatic arthritis of their non-dominant little finger DIPJ underwent arthrodesis in 30 degrees of flexion. Kirchner wires were inserted for up to 8 weeks to achieve fusion of the joint. Patients were evaluated after recovery using a dynamometer to assess grip strength, the DASH questionnaire and a sport specific questionnaire.

RESULTS

All arthrodeses achieved bony union without complication. All patients reported a resolution of their pain and recovery in their ability to catch & retain a ball. Measurements of grip strengths were comparable between hands. DASH scores improved by up to 47 points. All scores were less than 5 at final follow-up.

CONCLUSIONS

Grip strength decreases when fingers are immobilized in full extension. In sports that require catching or gripping a ball or a bat, arthrodesis of the DIP joint in flexion can improve grip strength and hand function. Fusion in 30 degrees of flexion for hurlers results in restoration of function and resolution of pain. Little finger DIPJ arthrodesis is a valid method of treating posttraumatic arthritis in ball and bat sports.

The Biomechanical Impact of Digital Loss and Fusion Following Trauma: Setting the Patient up for Success

Surgeons managing mutilating hand injures are faced with difficult decisions between attempting to salvage remaining or injured digits or proceeding to amputation and fusion. Through application of a basic understanding of hand biomechanics, the surgeon may more accurately predict what motion and function can best be salvaged. This article provides an explanation of how amputation, fusion, and tendon loss can affect postoperative hand motion. The surgeon can use these concepts in planning the reconstruction or preparing the foundation for secondary reconstructive procedures to achieve the highest functional outcome for the patient.

Simulated distal interphalangeal joint fusion of the index and middle fingers in 0° and 20° of flexion: a comparison of grip strength and dexterity

PURPOSE

To evaluate dexterity and grip strength after simulated distal interphalangeal (DIP) joint fusion of the index and middle fingers in varying degrees of flexion.

METHODS

Forty-six right-handed subjects performed grip and dexterity testing using the Grooved Pegboard Test in positions of index finger 20° flexion or full extension, middle finger 20° flexion or full extension, and unrestricted index and middle finger DIP joint motion (control). Simulated fusion was performed with the use of custom-molded thermoplastic orthoses.

RESULTS

Index finger dexterity scores were improved when the DIP joint was splinted in 20° compared with full extension. There was no significant difference in the middle finger dexterity when comparing 20° flexion with full extension. In either position, dexterity scores were higher (lower performance) for the index finger than for the middle finger, showing a greater interference to dexterity with splinting the index finger DIP joint. Mean grip strength was unaffected by middle finger DIP joint position, whereas splinting of the index finger in full extension resulted in reduced grip strength.

CONCLUSIONS

Because positioning the middle finger DIP joint in either extension or 20° of flexion did not significantly affect grip strength or dexterity, other considerations such as appearance can be given priority. For the index finger, however, positioning the DIP joint in 20° of flexion may improve grip strength and dexterity over positioning it in neutral.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.

An obliquely placed headless compression screw for distal interphalangeal joint arthrodesis

PURPOSE

To assess the outcomes of our technique involving oblique headless compression screw for arthrodesis of the thumb interphalangeal joint and the distal interphalangeal joints of the other digits.

METHODS

A total of 28 joints (19 thumb interphalangeal and 9 distal interphalangeal) in 23 patients with a mean age of 65 years (range, 58-74 y) were retrospectively analyzed. All operations were performed with the Acutrak2 micro-screw. After the resection of synovium and joint cartilage by a dorsal approach, a 0.88-mm diameter guide wire was inserted at the ulnar side of the proximal phalanx in the thumb and radial side of the middle phalanx in the other digits from proximal to distal to fix the joint obliquely. We verified its position under fluoroscopic control and placed the cannulated screw from proximal to distal over the guide wire.

RESULTS

Intraoperative rigid fixation was obtained except for 1 case, which required additional K-wire fixation. The overall union rate was 96%. Average time to fusion was 11 weeks (range, 8-30 wk), with 76% achieving union within 3 months. There were 2 complications, 1 nonunion and 1 late infection. Other complications such as dorsal skin necrosis, nail deformity, and paresthesia did not occur.

CONCLUSIONS

Efforts to avoid invasion of the nailbed can be technically demanding. We believe that our proximal to distal technique with oblique placement of the headless compression screw is a straightforward and effective method with a relatively low risk of complication.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

The quadriga phenomenon: a review and clinical relevance

The flexor digitorum profundus tendons are markedly interconnected, making them less able to move independently than the tendons of the flexor digitorum superficialis. This difference is often attributed to the common muscle belly of the profundus, but also, more importantly, to cross-connections between the tendons of the profundus. The effect of this quadriga phenomenon is important in several clinical situations, including testing for strength, assessing movement of the tendons, and when deciding which exercises to teach the patient after a tendon injury. The anatomy and biomechanics of this phenomenon are reviewed in this article to help explain why certain conditions occur, and to improve the diagnosis and treatment of some conditions in rehabilitation medicine.

Alternative to the distal interphalangeal joint arthrodesis: lateral approach and plate fixation

PURPOSE

Several fixation techniques for distal interphalangeal (DIP) joint arthrodesis have been described, with good clinical results and complication rates between 10% and 20%. We propose an alternative technique and fixation method using a lateral approach and 1.3-mm plate and screws fixation.

METHODS

Between March and September 2005, 11 patients, totaling 15 fingers, had DIP joint arthrodesis by the described technique. The indications were posttraumatic arthritis in 8 fingers, degenerative or rheumatoid arthritis in 5 fingers, and isolated flexor digitorum profundus tendon lesions in 2 fingers. Patients were analyzed for osseus union, pain relief, and functional mobility of the finger.

RESULTS

Arthrodesis relieved pain and restored stability at the 12th week, on average, with osseous union in all patients. All patients maintained full proximal interphalangeal joint motion with pulp-to-palm distance of zero at 6 months of follow-up evaluation. There were no rotational or angular deformities, nail bed lesions, or skin complications.

CONCLUSIONS

The lateral approach with plate and screws fixation is an option for DIP joint arthrodesis.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic IV.

Biomechanics and hand trauma: what you need

Mutilating hand trauma presents the surgeon with many reconstructive challenges. This article establishes some biomechanical guidelines to help the surgeon evaluate the hand trauma patient. Through a basic understanding of hand biomechanics, the surgeon may access more accurately what motion and function can best be salvaged. By understanding how amputation, fusion, and tendon loss impact on postoperative hand motion, the surgeon can better focus his or her reconstructive efforts to achieve the highest functional outcome for the patient.