Locked Wrist: A Case Report and Literature Review on Pisotriquetral Loose Bodies

Abstract

Background  Pisotriquetral (PT) loose bodies have been described in the literature only a few times as case reports. While PT pathology remains the differential for ulnar-sided wrist pain, it can often be difficult to diagnose, as symptoms can be variable and radiographic imaging may be negative for any findings.

Case Description  A 24-year-old major league baseball player presented with pain and locking of his wrist during follow through of his bat swing. Plain radiographic imaging, as well as computed tomography (CT) imaging, was negative for any pathology. Dynamic magnetic resonance imaging (MRI) demonstrated a loose body which entered the PT joint when the wrist was moved into a flexed position. This caused entrapment of the loose body and locking of the wrist.

Literature Review  A total of 17 reported patients in the literature have been diagnosed with a PT loose body. The clinical examination findings, radiographic findings, and surgical findings are reviewed.

Case Relevance  PT loose bodies can present a challenging clinical picture to diagnose. The purpose of this case report is to review the appropriate clinical workup, including common examination findings and advanced imaging techniques, to help the clinician with the diagnosis.

Loose bodies can be a source of joint pain in athletes, oftentimes occurring in this population due to the increased joint stresses from performing their specific sport. These osteochondral fragments may cause pain and a sensation of locking or clicking with movement of the joint. They are commonly found in larger joints such as the elbow, hip, and knee which can see larger joint reactive forces in athletes. Loose bodies within the wrist are less common and only a few case reports have discussed on loose bodies within the pisotriquetral (PT) joint specifically. Hall described PT loose bodies in a case report in two patients in 1981. ² This was followed by Steinmann et al, who reported on the largest series of PT loose bodies till date. ³ To the author's knowledge, there has been no report discussing PT loose bodies in a major league athlete.

Loose bodies may develop in the wrist after a traumatic injury or they can occur in a more gradual fashion in patients with underlying osteoarthritis. The physical demands and repetitive movements required in the athletic population may place these patients at an increased risk for developing loose bodies. Loose bodies within the PT joint can present a challenging clinical picture to diagnose. Oftentimes, radiographic imaging is inadequate in viewing the loose body and advanced imaging is necessary.

We present a case report of a PT loose body causing locking of the wrist in a major league baseball player and review the literature describing this injury. The physical examination findings, advanced imaging techniques, and surgical procedure are discussed.

Case Report

A 24-year-old, right hand dominant major league baseball player presented with pain in the volar ulnar aspect of his nondominant left wrist. He sustained the injury to his wrist sliding head first into base with impaction along the ulnar aspect of his wrist. He endorsed occasional locking of his wrist with certain movements. On examination, locking of his wrist was reproducible when the wrist was placed in flexion and ulnar deviation.

X-rays and computed tomography (CT) images were negative for an osseous abnormality and it was believed that a chondral fragment may have been free floating within the joint. Static and dynamic magnetic resonance imaging (MRI) scans were performed which demonstrated a 9 mm × 7 mm × 3 mm fragment in the PT joint. The dynamic study showed that during flexion, when the patient had the locking sensation, the loose body impinged between the pisiform and triquetrum. However, with extension of the wrist the fragment shifted outside of the joint ( Figs. 1 and 2 ).

Fig. 1.

Sagittal MRI cut of the wrist in an extended position demonstrating the loose body (white arrow) not impinging between the pisiform and triquetrum. MRI, magnetic resonance imaging.

Fig. 2.

Sagittal MRI cut of the wrist in a flexed position demonstrating the loose body (white arrow) now impinging in between the pisiform and triquetrum becoming entrapped. MRI, magnetic resonance imaging.

Surgery was completed and a large chondral fragment measuring 9 mm × 7 mm was able to be extracted from the joint ( Figs. 3 and 4 ). An incision along the dorsal ulnar capsule of the PT joint allowed entrance into the joint. The chondral fragment was able to be easily identified. Upon flexion of the patient's wrist intraoperatively, it was seen that the fragment abutted and impinged within the PT joint. Postoperatively the patient was immobilized for 2 weeks. Therapy was then initiated allowing active range of motion of the wrist with progression of palmar flexion over the following weeks. Once full active painless range of motion (ROM) and grip strength was achieved a gradual hitting sequence was started. He was able to get back to playing full time the following season and 1 year postoperatively is pain free with full ROM and full strength in his wrist.

Fig. 3.

Image demonstrating retraction of the abductor digit quinti in a volar direction with the elevator pointing to the pisotriquetral joint capsule prior to arthrotomy.

Fig. 4.

9 mm × 7 mm chondral fragment after excision from the pisotriquetral joint.

Discussion

PT loose bodies are an uncommon finding which may lead to locking of the wrist. The PT joint is a complex joint due to its various ligamentous attachments. Cadaveric and biomechanical studies have demonstrated that the pisiform has multiple soft tissue attachments which help to stabilize the joint in different planes. The primary stabilizers of the PT joint include the pisohamate ligament, pisometacarpal ligament, and PT ligament which help to stabilize the pisiform from proximal, ulnar, and radial displacement, respectively. ^{5 6 7} Acute or chronic injuries to the pisiform ligamentous complex can lead to PT instability. Altering the normal PT joint mechanics increases stress across the joint placing the patient at higher risk of developing chondral lesions, wear, and the development of loose bodies.

Additionally, cadaveric and arthroscopic in vivo studies have demonstrated that the radiocarpal joint connects with the PT joint in the majority of patients, 50 to 88% of the time. ⁸ Thus, injury or irritation to any part of the radiocarpal joint may predispose patients to the development of intra-articular loose bodies within the wrist which may then become entrapped within the PT joint. The pisiform is in close articulation with the triquetrum when the wrist is in an extended position but when the wrist moves into a flexed position, the PT joint opens up allowing space between the two bones. ⁹ This can explain why our patient developed locking of his wrist when he entered into a flexed position of his wrist as the loose body was able to fit in between the pisiform and triquetrum.

Loose bodies within the PT joint are an uncommon finding and thus have been described in the literature only a few times in the form of case reports. ^{1 2 3 4 5 7 10} Both acute traumatic events, as well as chronic repetitive wrist motions, typically from occupational demands, have been described as the causative factors for development of the loose body. In our review of the literature, we found 17 reported cases of loose bodies in the PT joint, including our case. The patient demographics, symptoms, imaging findings, and intraoperative findings are listed in Table 1 .

Table 1. Patients' demographics, symptoms, imaging findings, and intraoperative findings.

Case	Study	Age/sex	Symptoms	XR images	Treatment	Joint
1	Hall 2	52/M	USWPOF, locking, numbness	Normal	Removal LB	Normal
2	Hall 2	42/M	Pain/paresthesias in hypothenar muscles	Diagnostic	Removal LB	Normal
3	Needoff and Frostick 6	42/F	USWPOF, locking	Diagnostic	Removal LB	Normal
4	Needoff and Frostick 6	58/F	USWPOF, locking	Diagnostic	Removal LB	Degenerative
5	Steinmann and Linscheid 3	24/M	USWPOF	Negative	Removal LB, pisiform excision	Degenerative
6	Steinmann and Linscheid 3	20/M	USWPOF	Negative	Removal LB, pisiform excision	Degenerative
7	Steinmann and Linscheid 3	63/F	USWPOF	Diagnostic	Removal LB	Normal
8	Steinmann and Linscheid 3	49/F	USWPOF	Negative	Removal LB	Normal
9	Steinmann and Linscheid 3	50/F	USWPOF	Diagnostic	Removal LB, pisiform excision	Degenerative
10	Steinmann and Linscheid 3	69/F	USWPOF	Diagnostic	Removal LB	Normal
11	Steinmann and Linscheid 3	73/F	USWPOF	Negative	Removal LB, pisiform excision	Degenerative
12	Steinmann and Linscheid 3	56/F	USWPOF	Diagnostic	Removal LB, pisiform excision	Degenerative
13	Hibino et al 4	48/F	USWPOF	Diagnostic	Removal LB	Normal
14	Katolik 5	19/M	Wrist pain with extension and flexion	Negative	Removal LB	Normal
15	Dumontier et al 1	54/F	Wrist pain with extension	Diagnostic	Removal LB	Degenerative
16	Williams et al 10	51/F	USWPOF, locking of bilateral wrists	Negative	Removal LB from both wrists	Normal
17	Present study	24/M	USWPOF, locking	Negative	Removal LB	Normal

Abbreviations: F, female; LB, loose body; M, male; USWPOF, ulnar sided wrist pain on flexion; XR, X-ray.

Note: the demographics of the 17 reported cases include 6 males and 11 females. The average age of the patients was 46.7 years old. On examination of the pisotriquetral joint at the time of loose body removal, 8/17 demonstrated significant degenerative wear patterns.

During the initial workup, imaging is helpful to determine the source of the patient's symptoms. The presence of an osseous loose body can help make the diagnosis with the use of routine X-ray images. However, oftentimes X-ray images may be negative for any abnormality, making the diagnosis more challenging. In our review of the literature, X-ray imaging was diagnostic in only 52.9% (9/17) of the cases. This highlights the importance of utilizing advanced imaging. We found the dynamic MRI scan to be extremely valuable in our case. Static MRI images demonstrated synovial hyperplasia around the PT joint but when flexing and extending the wrist with the use dynamic MRI, the loose body was able to be seen moving in and out of the PT joint. Advanced imaging may be essential in certain cases, as standard imaging modalities may not appropriately demonstrate the chondral loose body, and clinical exam maneuvers have not been shown to be specific for loose bodies within the PT joint.

In our review, the majority of cases (88%) demonstrated ulnar-sided wrist pain with flexion of the wrist. As discussed earlier, with flexion of the wrist, the pisiform and triquetrum move apart allowing more space between the two bones. ⁹ If a loose body is present, flexion of the wrist could facilitate passage of a loose body into the PT joint which then impinges in the joint eliciting pain. If the loose body is large enough and becomes entrapped in the joint, this can lead to locking of the wrist. Locking of the wrist was reported in six cases, including our own.

Our patient, a right-handed batter, experienced locking of his left wrist when following through during his batting sequence. At this point his wrist was in an ulnar deviated and flexed position facilitating ingress of his loose body into the PT joint.

Conclusion

It is important as clinicians to keep a broad differential diagnosis when athletes present with ulnar-sided wrist pain. Causes of ulnar-sided wrist pain which should be considered include triangular fibrocartilage complex (TFCC) pathology, ulnocarpal impaction, distal radioulnar joint instability, flexor carpi ulnaris/extensor carpi ulnaris tendinopathy, hook of the hamate fractures, and ulnar artery thrombosis, including others. It is important to keep PT pathology on the differential, specifically when patients complain of volar ulnar wrist pain and have locking of their wrist. Additionally, utilizing advanced imaging techniques, such as dynamic MRI, may help diagnose PT loose bodies and allow appropriate treatment.