Saddle syndrome (Chicarilli, Watson, Linberg, & Sasaki, 1986) occurs when adhesions form between the dorsal or palmar interosseous tendons and the lumbrical tendons on the volar side of the hand. This phenomenon was first described by Watson, Ritland, and Chung (1974), who reported 12 cases that required surgical release. These two musculotendinous units straddle the deep transverse meta-carpal ligament (dTML), analogous to legs on either side of a saddle (Figure 1). The lumbricals arise from the volar surface on the radial side of the index, long, ring, and small fingers, and they route anterior to the dTML and insert into the dorsal hood mechanism. The second dorsal and third and fourth volar interossei are also located on the radial side of the long, ring, and small fingers, and they route dorsal to the dTML. Adhesions can form between the dorsal and/or volar interossei and the lumbricals either distal to (Figure 1, part 1) and without involvement of the dTML or directly to the dTML (Figure 1, part 2). In the first case, where the adhesions are distal without dTML involvement, pain occurs during the intrinsic plus position when the muscles are contracted (Figure 1, part 3). As the muscles contract, the dTML divides the two adhered muscles, resulting in pain. In the second case, where there is adhesion to the dTML, pain occurs during the intrinsic minus position. When the meta-carpophalangeal joint (MCPJ) is extended and the inter-phalangeals are flexed, the muscles are stretched and pulled away from the dTML (Figure 1, part 4). This movement strains the adhesions to the dTML, causing pain. Another way to visualize the interaction of the dorsal interossei, the lumbricals, and the dTML is to visualize the dTML as a piece of paper between two levers of a pair of scissors, where the dorsal lever is the interossei and the volar lever is the lumbricals. Adhesions may form as a result of increased inflammation caused by trauma to the area and decreased use of the hand as a result of edema and protection after injury. Common causes of this injury include crush injuries, a contusion from a direct blow, a fall on an outstretched hand, and torquing stresses; in addition, sequelae from infections are possible (Chicarilli et al., 1986). Accurate diagnosis is best made through intraoperative observations, and magnetic resonance imaging can help to confirm the diagnosis (Tan, Rothenfluh, Beredjiklian, Potter, & Weiland, 2002). The clinician typically makes the diagnosis based on a thorough clinical examination (Chicarilli et al., 1986).
Part 1: The dorsal interosseous (DI) and lumbrical (L) tendons are adhered (see magnification) as they form a “saddle” over the deep transverse metacarpal ligament (dTML). Part 2: The dorsal interosseous and lumbrical tendons are adhered to the dTML. Part 3: The dTML itself is not adhered; however, as the dorsal interosseous and lumbrical tendons contract, they divide the two adhered muscles, resulting in pain. Part 4: Adhesion of the dorsal interosseous and lumbrical tendons to the dTML. Pain occurs when they are pulled away and distracted from the adhesion, as in interphalangeal joint flexion with metacarpophalangeal joint extension. [Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.]
A 38-year-old man fell from a horse onto his outstretched hand, sustaining a fracture-dislocation of the right dominant elbow and the tip of the coronoid process. He underwent closed reduction of the elbow, followed by immediate controlled active range of motion in a hinged elbow orthosis with a 45° extension block for the first 3 weeks. After that, he had weekly progression of extension by 15° to achieve full (0°) extension by 6 weeks. During the initial outpatient occupational therapy evaluation, he reported pain in the elbow and along the dorsal aspect of the MCPJs adjacent to the second, third, and fourth web spaces. He rated the pain of the hand in the web spaces as 8 of 10. Examination showed visible swelling over the dorsum of the involved MCPJs, and the circumference of the hand at this level measured 21.5 cm (compared with the left side, which measured 20 cm). Palpation produced tenderness in the second, third, and fourth web spaces between the metacarpal heads. No pain was reported with active abduction or adduction, but the client had significant tightness and markedly elevated pain with MCPJ extension and interphalangeal flexion (intrinsic minus position) combined with passive abduction of the adjacent digits (Figure 2). Hand radiographs were obtained and read as negative. Pain is the greatest finding that differentiates saddle syndrome from intrinsic tightness. The pain is described as deep, and there is point tenderness with palpation dorsally between the meta-carpals with deep pressure. The diagnosis can be confirmed by the finding of increased pain with passive or active abduction of the MCPJs with concomitant interphalangeal flexion and MCPJ extension (Figure 2). Although this has not been officially researched as a differential test for saddle syndrome, we have used it effectively.
A maneuver that may produce pain with saddle syndrome: metacarpal phalangeal joint extension with interphalangeal joint flexion combined with passive abduction.
Therapeutic measures included soft tissue massage of the intrinsic muscles in the involved web spaces as well as low-load prolonged stretch into an intrinsic minus position (Figure 3). The therapist applied soft tissue massage with the client's hand in a resting position and relaxed posture in a pain-free fashion over the second, third, and fourth intermetacarpal spaces for 7 to 10 minutes. Therapists may use the proximal interphalangeal joint of their own hand to apply gentle but targeted release. Low-load prolonged stretch was completed during each session and as part of the client's home program training. This consisted of three to four repetitions of 20 to 30 seconds of hold in an intrinsic minus position at end-range tension. The client reported discomfort of less than 4 of 10. The client was trained to repeat this movement every other hour throughout the day when not in the clinic. The therapist instructed the client in mobility of the intrinsic muscles as part of the home program. This included tendon gliding with active range of motion through intrinsic minus, intrinsic plus, finger flexion, composite flexion, and abduction and adduction of the fingers (Figure 4). Sessions included fluidotherapy to allow for additional mobility with a heat modality. The client attended therapy sessions twice per week initially. By the eighth session, the client and the therapist noted improved functional abilities with the hand for typing and fine motor tasks. The client also reported only mild pain with palpation and stretch to intrinsic muscles, with a pain score of 0 of 10 at rest. He was able to complete a fist with the fingertips approximating the proximal palmar crease compared with 50% of full fist on the first visit. The client reported the greatest pain with stretching to the intrinsic muscles initially, with a visual analog scale score of 8 of 10. He reported a pain score of 0 of 10 with the same maneuver at 8 weeks (Figure 2). The therapist reviewed the client's occupational profile, and he reported resuming the use of a mouse and keyboard for his job without difficulty. The client was discharged after completion of therapy for the return of function to his elbow after the initial fracture. He no longer reported pain or lingering tightness in the hand or fingers at the time of discharge. He reported having full function of the fingers and hand for all work and self-care tasks. He has not returned to recreational tasks (e.g., playing baseball) because of mild limited elbow function; however, he plans to return to his recreational activities gradually over the next several months. The change of score in outcome measures is shown in Figure A (available in the online version of the article). After eight therapy visits over a 4-week period, two times per week, the client had a score of 0% disability on a visual analog scale of function and the short version of the Disabilities of the Arm, Shoulder and Hand (QuickDASH) outcome measure (Hudak et al., 1996).
The client was instructed in low-load prolonged stretching into intrinsic minus positioning. Arrows indicate interphalangeal flexion with stretch with concomitant metacarpophalangeal extension. [Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.]
Exercises to promote mobility of the intrinsics with tendon gliding. Hook fist (A). Intrinsic plus position (B). Long fist (C). Full fist (D). Finger abduction (E). [Used with permission of Mayo Foundation for Medical Education and Research, all rights reserved.]
Key: VAS= visual analogue scale; MCP=metacarpal phalangeal; circ=circumference; subjective functional loss based on items patient told therapist verbally (7, 2, 0 functional difficulties); subjective loss of strength based on occupational profile with patient; ROM indicates a 4 cm lag on intake/50% of full fist; QuickDASH was not administered first day of treatment; at discharge was a 0 percent disability. Very short bars= score of “0”
Although clients are referred to therapy for treatment of a specific injury, the therapist sometimes finds related problems involving soft tissue and/or skeletal structures at different sites (Forward, Lindau, & Melsom, 2007). A skilled therapist must be able to identify these additional complicating or painful issues and address them appropriately or bring them to the attention of the referring provider for further diagnostic evaluation, such as imaging studies. Failure in this regard can result in chronic or residual pain or lingering loss of function.
In this case, the therapist took the time to listen to the client at the time of intake and perform a careful assessment of the anatomy to identify the root cause of the client's symptoms. This approach allowed the therapist to focus on the intrinsic muscles and dTML of the hand while attending to the initial reason for referral, which was an elbow fracture. Initially, this client was referred for postreduction therapy after an elbow fracture-dislocation with involvement of the coronoid process. Additional testing during the occupational therapy evaluation identified pain and decreased motion in the hand that limited functional use of grip. Pain while testing for intrinsic tightness is a key sign of saddle syndrome (Figures 2–3). Although the client had stiffness and loss of motion, deep pain was the primary factor that interfered with function. The therapist adjusted the treatment plan to address both the elbow injury and pain and weakness in the hand. As a result, the hand pain resolved and the client's grasp and function subjectively improved.
In many cases, persistent pain with saddle syndrome is relieved through surgical release of the adhesions (Chicarilli et al., 1986; Topper, 1997). This is a relatively simple procedure (Muder & Vedung, 2014), but it still carries the risks associated with surgical intervention. Chicarilli et al. (1986) reported that all patients (n = 87) except for three returned to their previous employment within an average of 4 to 6 weeks after surgery. Moreover, Muder and Vedung (2014) reported complete resolution of function at 12-month follow-up in their single case, with no explicit outcome measures mentioned. Fortunately, in our experience, symptoms may be resolved nonoperatively.
Limitations of this case report include the lack of measurable outcomes and the inclusion of only one subject. The research would be strengthened by a prospective case series of saddle syndrome. A literature search did not identify any other accounts of nonoperative treatment, successful or otherwise, of saddle syndrome. Additional study of the clinical effectiveness of various treatment options would add to the validity of treatment choices. Additional research is needed to identify the frequency of saddle syndrome concurrent with the diagnosis of a fall onto an outstretched hand or another traumatic injury. A prospective case series of therapeutic interventions for pain caused by interaction of the dTML and the intrinsic muscles will help to identify best practices and the efficacy of intervention by hand therapists.
Therapy includes the use of heat, tendon gliding, soft tissue mobilization to the intrinsic musculature, and low-load prolonged stretch in either the intrinsic plus or intrinsic minus position, depending on the location of the adhesions. Although this treatment is similar or identical to the treatment of tightness of the intrinsic muscles, saddle syndrome should be differentiated because it causes pain and may occur early in the posttraumatic healing process and distal to the site of injury. Pain may draw attention away from the rehabilitation process and lead to further dysfunction. The client may be reassured to learn that there is a valid anatomic reason for the pain and that the therapy is targeting both the pain and its root cause, which is the formation of adhesions between the dorsal and/or volar interossei and the lumbrical muscles either distal to, and without involvement of, the dTML, or directly to the dTML. Soft tissue mobilization targets deep tissues, including the dTML, along with the interossei and lubricals as they arise off the flexor digitorum profundus tendons. Resolving pain allows more rapid return to functional use of the hand, which prevents stiffness, helps to decrease edema, and increases self-efficacy and quality of life.
- Chicarilli, Z. N., Watson, H. K., Linberg, R. & Sasaki, G. (1986). Saddle deformity. Posttraumatic interosseous-lumbrical adhesions: Review of eighty-seven cases. Journal of Hand Surgery, 11(2), 210–218. https://doi.org/10.1016/S0363-5023(86)80053-3 PMID: doi:10.1016/S0363-5023(86)80053-3 [CrossRef]3958449
- Forward, D. P., Lindau, T. R. & Melsom, D. S. (2007). Intercarpal ligament injuries associated with fractures of the distal part of the radius. Journal of Bone and Joint Surgery–American Volume, 89(11), 2334–2340. doi:10.2106/JBJS.F.01537 [CrossRef]
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- Muder, D. & Vedung, T. (2014). Interosseous-lumbrical adhesions secondary to an infection: A case report. Journal of Medical Case Reports, 8(1), 301. https://doi.org/10.1186/1752-1947-8-301 PMID: doi:10.1186/1752-1947-8-301 [CrossRef]25200654
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- Topper, S. M. (1997). Symptomatic adhesions of the index interosseous-lumbrical tendons: A case report. Journal of Hand Surgery, 22(6), 1025–1026. https://doi.org/10.1016/S0363-5023(97)80042-1 PMID: doi:10.1016/S0363-5023(97)80042-1 [CrossRef]
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