Saba Kamal, OTR, CHT
- Case reports
- Introduction
- Purpose of the orthosis
- Materials
- Fabrication steps
- Fabrication components
- Supplementary data
- References
Highlights
- Allows for limited protected movement of the MCP joint of the index finger with use
- Prevents MCP joint of the index finger contracture
- Allows for less rehab time
- Improves compliance to splint wear
- Prevents recurrence of injury
Case reports:
1st case: Pre-Op RCL injury
Patient, a pro-tennis player 32 years old, presented with RCL strain grade II on MRI3, secondary to incorrect taping of the wrist, which resulted in incorrect racquet handling, leading to strain of RCL of the index finger. This patient was treated with night MP blocking splint (hand based, MP extended and IP’s free) and a day wide buddy loop splint. Pt was taped with leukotape during practice sessions and games to avoid ulnar deviation of the Index finger
Results: MRI3 was repeated after season was over, pt. presented with good healing and no pain and tenderness over RCL
2nd case: Post op repair of RCL 3 weeks post op.
Pt. presented 3 weeks post op with swollen stiff fingers, no movement at the MP joint and limited movement at the PIP and DIP joints with the hand placed in a half cast with the entire hand in 0o of MP flexion.
This patient was splinted in the MP blocking splint (Hand based MP joint at 0o of flexion for the index and middle finger, PIP free) for an additional 2 weeks but removed for gentle protected (Neutral deviation at index finger MP joint) exercises. At 5 weeks, pt. was provided with a wide buddy loop during the day and the MP splint at night, to allow for early active ROM. Pt. was allowed to move it but not use it.
The wide buddy splint prevented full MP flexion due to its design thus preventing any loosening of the surgical repair. The night splint was discharged at 8 weeks along with the wide buddy loop, after ensuring stability of the repair & decrease in pain.
The wide buddy loop helped with reducing swelling by allowing early motion. It also helped prevent complications like stiffness due to extended casting or using regular buddy loops which doesn’t protect the repair as the index finger is pulled towards the stable middle finger thus stretching the RCL of the Index MP joint thus loosening the repair, resulting in pain and decreased pinch strength.
Exercises given to the post op patient were, peg rolls to enhance finger movement and putty rolling to ensure full MP/PIP extension. Once stable, strengthening exercises were added.
Results: Improved pinch strength with no pain, and enhanced function.
RCL injury to index MP joint occurs mostly due to trauma, force pushing the index finger in flexion and ulnar deviation at the MP joint of the index finger resulting in attenuation or tear of the radial collateral ligament of the MP joint of the Index finger. It may create pain and weakness in pinch in patients after trauma especially with hypermobility and 1st CMC joint OA. This may result in radial pinch pattern due to lack of the pulp to pulp pinch because of the arthritis at the base of the thumb. Over time chronic instability may lead to pain, weakness, and arthritis5 especially with pinch and grip further exaggerating the deformity. This pinch pattern hyper-pronates the index finger thus adding to the trauma.
Test: Level of injury is tested by flexing the MP joint in flexion and ulnarly deviating it. With MP in flexion the collateral ligament is at maximum stretch and ulnarly deviating at its maximum stretch will provide information of the amount of attenuation or tear of the ligament. If the finger is tested in extension the ligament is lax and thus there is more motion with MP in extension than in flexion resulting in incorrect results or the assessment. Grades are defined as follows:
Grades: Grade 1 defined as (tenderness over RCL, no instability), grade 2 (laxity compared to the contra-lateral digit with a definite endpoint), or grade 3 (laxity without endpoint)1. Early presentation is defined as less than four weeks and late greater than four weeks.1
Traditional treatment included:
Casting, Buddy straps, Aluma-foam and if none of the conservative treatment2 worked a surgical Repair/ Reconstruction or fusion is done.
Purpose of the orthosis
The purpose of this orthosis is to demonstrate a better approach to managing patient with RCL of the MP joint involvement of the index finger. Significant stresses are placed on the radial side of the MCP joint of the index finger4 with pinching / gripping. Where typical treatments have failed2 due to casting in MP extension (slack position) for extended periods to allow for tightening of the ligament or buddy taping that fails to correct the problem as it allows for pinching and full motion with ulnar drifting of the finger, this splint design offers new light to treating patients with this injury.
Reason for a new treatment approach
This splint allows for limited AROM in a protected position with improved compliance and minimal secondary problems.
The reason for a new approach is to present a new option where previous choices have failed. Reason for failure is as follows with specific techniques used in the past.
Grade I – if buddy strap is used, the buddy straps pulls the index finger towards the middle finger during pinching causing it to ulnarly deviate thus exaggerating the problem and causing failure of treatment.
Grade II-III – Aluma foam or casting is used. Casts can be too bulky and prevents function resulting in poor compliance with splint wear, thus resulting in failure of treatment
Materials

Fabrication Steps:

2 Cuffs are fabricated around the Index and Middle finger respectively by wrapping the thermoplastic around each finger and pinching the ends together, the ends of the cuff must be away from the ulnar aspect of middle and radial aspect of ring finger.
After the two cuffs are conformed around the finger, they are then opened, and the ends are cut to allow for changes in swelling by use of Velcro.

An insert to encourage neutral positioning of the index finger to its metacarpal is used
Solvent to remove any adhesive coating is applied to all materials. And the finger insert is then attached based on the angulation needed to keep the index finger in alignment to its metacarpal and prevent deviation of the finger. The two fingers index and middle are then held together with the finger insert. The cuffs of the Wide buddy loop are adjustable to accommodate for the change in hand swelling after surgery.
Nail paint is used at one end to remind the patient which way to wear the splint.
Wearing time:
Wearing the wide buddy loop during daytime prevents ulnar deviation of the index finger thus protecting the finger. Due to the spacer it also somewhat limits full flexion of the finger with activities. Patient is encouraged to move it but not use it for aggressive movements like opening jars, cans etc.
Wearing the splint prevents stiffness of the MP joint due to the protected movement allowed by the splint. Thus, reducing the number of visits seen in therapy.
Results:

Grade I responds to the wide buddy loop treatment in around 3-4 weeks wearing it 23/7.
Grade II and III – 5-6 weeks, may require hand-based MP extension splinting at night and wide buddy loop during the day for optimum results. MCP is kept in extension to prevent stretch on the already stretched ligament and for it the develop a new shortened resting length to hold the joint stable.
Grade IV requiring surgical repair2, patient is fitted with MP extension splint initially after surgery for 3-4 weeks at all times, then to wide buddy loop during the day and MP extension splint at night for another 2 weeks, finally the night splint is discharged and wide buddy loop is continued for another 2 weeks until patient demonstrates stable pinch patterns. Wide buddy loop splint encourages function yet protecting the repair, thus allowing early motion. If patient is involved in sports, taping is used. Once the repair is deemed stable to pinch and griping activities the wide buddy loop is discharged.
Benefits of Wide buddy loop: Easy to wear, allows enough movement to perform light functional activity, however, prevents complete flexion of the finger or a tight fist. Prevents ulnar deviation of the index finger thus protecting the injury and preventing it from worsening and allowing healing to occur. Recovery process is smooth due to increased compliance from the patients on splint wear.
Improved prehension pattern of the thumb and index finger protecting the MCP RCL. However, we did note that the PIP joint is stressed in some cases especially when 1st CMC joint arthritis is present resulting in lateral pinch instead of the pulp to pulp. The splint ends up protecting the MCP but the patient has to be educated on pinching to avoid strain to the PIP joint of the index finger.
The two cases chosen to demonstrate typical outcomes of therapy following RCL pre/post op injury, all demonstrated improved PSFQ scores, decreased pain, and satisfaction with early motion and improved strength.
Discussion:
Casting of the patient s/p surgery may result in contracture of the MP joint and allowing motion without proper support may result in loosening of the repair. Thus, minimal protected movement without excessive use prevents both the contracture of the finger and loosening of the repair.
The significance of this injury remains underestimated and requires a high index of suspicion.1 Early correct splinting is crucial to successful treatment. For successful treatment compliance is incredibly important. Its proven, bulky splints have reduced compliance as it inhibits function. Thus, the wide buddy loop serves that gap and allows for successful conservative management of the RCL injury for grade I, II without surgery and early motion protocol after surgery thus minimizing the risk of post op complication.
Excellent outcomes have been achieved using the protocol for pre/post op RCL injury. The timing of the night extension splint has varied from 3-5 weeks depending on the laxity / instability the patient presented with in other cases. Future investigation is needed to determine the optimal timing of night splint wear, the number of treatment sessions, & to continue to monitor for adverse effects and attainment of functional goals.
References:
- Radial collateral ligament injury of the index metacarpophalangeal joint: an underreported but important injury, by R Glenn Gaston, Gary M Lourie
- Rupture of the radial collateral ligament of the index metacarpophalangeal joint: diagnosis & surgical treatment. by Lana Kang et al
- Imaging in index finger radial collateral ligament injury: attention to detail really pays…. Chotai NC el al.
- Rupture of the radial collateral ligament of the metacarpo-phalangeal joint of the index finger: a report of three cases. Doyle JR, Atkinson RE.
- Collateral ligament injuries of the metacarpophalangeal joints of the fingers. Lourie GM, Gaston RG, Freeland AE.