Keywords
Volar Plate - PIP Joint Fractures - Proximal Phalanx Head Fractures - Resurfacing
- Arthroplasty
Introduction
Volar plate arthroplasty (VPA), popularized by Eaton and Malerich,[1] is a well-established technique for providing mobile proximal interphalangeal joints
(PIPJs) for injuries with severe comminution of the middle phalanx (MPx) base.[2] However, use of the volar plate in severely comminuted fractures of the head of
the proximal phalanx (PPx), especially acute scenarios, is inadequately established
in literature. Some texts even mention fractures of the head as a contraindication
for VPA.[3] We present a rare case of comminuted fracture of the head of PPx which was not amenable
to reconstruction. We performed a volar plate draping to resurface the raw phalangeal
neck, in anticipation of providing a mobile joint to this young patient who understood
the uncertain nature of the operation. He attained an extremely satisfactory, painless,
range of movement, and was extremely happy about the outcome, encouraging us to report
this technique for wider use in such injuries.
Case Report
A 20-year-old male presented with a closed, severely comminuted fracture of the head
of PPx with PIPJ dislocation of the right middle finger. Open reduction of the joint
was planned under regional anesthesia. Volar plate was reflected as a proximally based
flap. The head of the PPx was extremely comminuted, with small bony fragments that
could not be replaced ([Fig. 1]). Since the volar plate was uninjured, it was used to create an even articulating
surface. Removal of the bony fragments along with 5-mm shortening of the PPx neck,
necessitated by the extensive damage, reduced the height of the PPx enough to allow
the volar plate to be flipped over the distal portion of the PPx, from volar to dorsal
side. It was then sutured dorsally, to the periosteum and capsule on one side and
using Prolene suture taken through a drill hole in the bone, on the other side ([Fig. 2]). This provided a contoured surface that articulated well with the base of the MPx.
After closure, the PIPJ was stable, maintained by the tension of the flexor and extensor
tendons. Ten degrees of lateral deviation noted intraoperatively, was managed by buddy
strapping the middle finger to the index and ring fingers. Range of motion (ROM) intraoperatively
was 110 degrees of flexion at the PIPJ, and complete extension. Active mobilization
of the finger was started on day 1.
Fig. 1 Comminuted fracture of the proximal phalanx head with multiple loose fragments.
Fig. 2 Schematic representation and clinical photograph demonstrating volar plate draping.
The patient maintained 100 degrees of active ROM throughout follow-up. Physiotherapy
included protected mobilization for 4 weeks, day-to-day activities at 4 weeks, and
normal use at 8 weeks. He maintained an excellent ROM throughout, with a total active
flexion score of the American Society for Surgery of the Hand of > 220 degrees, and
no palm-tip distance. At 3-year follow-up, his ROM at the PIPJ was 110 degrees, painless,
and smooth ([Supplementary Video 1]). He also used his hand for routine and rigorous activities like sports and weightlifting.
A slight ulnar deviation of the finger at the PIPJ was noted, which did not cause
instability, malalignment, rotation, or crossing over of the finger ([Fig. 3]) ([Figs. 5A–D]).
Fig. 3 Check radiographs revealed the neck cut in the proximal phalanx to be sloping ulnar
wards.
Discussion
PIPJ fracture dislocations are estimated to be 1 to 10 in 100,000 patients[4] and mismanaged injuries in the PIPJ can result in arthritis of the joint. With a
ROM of 10 degrees hyperextension to 110 degrees flexion, PIPJ has 100 to 120 degrees
arc of motion, constituting approximately 85% of the finger flexion in grasp.[2]
[5] Thus, preserving PIPJ movement should be a priority. For comminuted fractures of
the MPx base, time-tested operations include volar plate and hemi-hamate arthroplasties.[1]
[3] However, for uncommon, comminuted fractures of the PPx head (London type III)[5]
[6] no specific treatment protocols exist. A surgery that provides painless, free movement
of a joint, any day surpasses arthrodesis, which functionally reduces pinch aperture,
strength, and coordination between all the fingers, required for daily function,[7] especially significant in younger patients.
Two important factors in achieving good range of movement at the PIPJ are concentricity
of the articular surfaces and early ROM.[5] Joint stability is provided by the shape of the MPx that fits on the head of the
PPx, along with soft tissue structures. Concentricity of the surfaces with respect
to each other enables them to work in sync, naturally maintaining stability through
the range of movement. Since the MPx base was intact, in our patient, the focus was
to recreate the impaired contour of the head of PPx by draping the thick volar plate
over the remaining neck of PPx, which cannot be achieved by the standard Tupper's
arthroplasty. PPx head fractures are contraindicated in VPA,[3] which will fail without an intact PPx head to support it.
The structure of volar plate, described as having a distal fibrocartilaginous portion
and a proximal membranous portion,[8] is ideal to recreate the shape of the head of PPx. The distal portion provides the
appropriate tissue for the joint surface because of the tenosynovium lining the volar
aspect of the plate, and a fibrocartilaginous core that provides the sturdiness; while
the proximal membranous portion allowed mobilization of the volar plate.
The success of this procedure relies on several important factors. First, the volar
plate should be uninjured, and precautions should be taken to ensure the distal and
proximal ends of the volar plate are intact. Second, the radial and ulnar edges of
the distal PPx should be at the same level. Unequal ends may result in deviation of
the finger. Third, collateral ligament integrity should be ascertained, just as in
Tupper's arthroplasty, which is crucial for stability of the joint. Stability and
range of movement of the joint can be assessed intraoperatively by doing a squeeze
test, as was done in our case.
Conclusion
This procedure converts the joint stability system from that of a combined bony and
ligamentous support system to a soft tissue-centered support system. Follow-up of
more cases will establish this as a probable standard of treatment for London type
III PPx head fractures. Three-year follow-up of this patient ([Fig. 4]) has given us a strong belief that this procedure can provide an excellent ROM and
a functional finger, without pain, when there is severe articular comminution that
cannot be managed by the current modes of treatment.
Fig. 4 Clinical outcomes after 3 years.
Supplementary Video 1 Range of movement at three years follow up.
Fig. 5 (A) Preoperative Xray AP view. (B) Preoperative xray lateral view. (C) Post operative follow-up xray AP view. (D) Post operative follow-Up xray lateral view.
