Background/Objectives: Many patients evaluated by shoulder specialists suffer from intractable pain, neuropathy, and weakness. The pectoralis minor (PM) remains the only scapula muscle to receive lower trunk (C8-T1) input. We propose a novel syndrome: the Human Disharmony Loop. This model portrays how this unique PM innervation causes scapular dyskinesia, which deranges the anatomy of the upper limb girdle and produces a refractory symptom complex of pain, neuropathy, and weakness. We hypothesize that certain patients with historically intractable symptoms of the upper limb girdle may benefit from PM tenotomy. Methods: Ten patients of diverse etiologies presented with a similar constellation of complaints. The patients included a female athlete, a female with macromastia, a male bodybuilder, and patients with post-radiation breast cancer, post-operative shoulder arthroplasty, interscalene block injury, cervical spine disease, persistent impingement after rotator cuff repair, direct traction injury, and occupational disorder. All patients exhibited coracoid tenderness, scapula protraction with internal rotation and anterior tilt, and pain involving the neck, shoulder, and upper back. The patients demonstrated varying degrees of arm neuropathy, subacromial impingement, and occipital headaches. The patients failed all prior treatments by multiple subspecialists, including surgery. Each patient underwent isolated open PM tenotomy. Results: In all ten patients, PM tenotomy substantially reduced shoulder, upper back, and neck pain, cleared concomitant neuropathy, restored full motion, and eradicated occipital headaches. The response to surgery was rapid, dramatic, and durable. Conclusions: The unique asymmetric neurologic innervation to the sole ventral stabilizer of the scapula, the pectoralis minor, predisposes the human shoulder to neurologic and musculoskeletal imbalance. This produces the Human Disharmony Loop: a clinical syndrome spanning from the neck to the fingertips, with chronic pain, neuropathy, and weakness. These challenging patients may benefit dramatically from isolated PM tenotomy.

Background/Objectives: Patients commonly present with a mix of intractable shoulder pain, persistent impingement/loss of shoulder motion, neck pain, headaches, and distal neuropathy. These patients are notoriously resistant to surgical and non-surgical treatments. Previously we proposed the Human Disharmony Loop (HDL) as a model that anatomically explains these symptoms and diagnostically predicts successful response to surgical intervention. The purpose of this study is to validate positive surgical treatment outcomes in patients diagnosed in the HDL via retrospective chart review. We hypothesized that pectoralis minor release would reliably decrease pain and occipital headaches and increase shoulder motion for patients who met diagnostic criteria for the HDL. Methods: Patients diagnosed with the HDL and treated with pectoralis minor release at two separate institutions with at least 6-month follow-up were included. Diagnosis was based on explicit anatomic and symptomatic criteria: coracoid tenderness, scapular protraction, and at least one end symptom. Neuropathy was tested using the scratch-collapse test. Outcomes included pain scores, clinical neuropathic lesions, rotator cuff impingement signs, shoulder range of motion, and complications. Results: 115 patients were included. Average age was 48. 37% were male. 89% of patients who received a preoperative subcoracoid injection reported a significant decrease in presenting symptoms. 6 months after PM release, median VAS pain scores decreased from 8 to 2. Occipital headaches decreased from 66% to 6%. Rotator cuff impingement decreased from 87% to 10%. Median shoulder abduction increased from 90 to 180 degrees. Neuropathy decreased at the following locations: scalenes 57–2%, suprascapular 51–0%, quadrilateral 81–5%, radial 60–11%, cubital 31–25%, carpal 53–25%. 25% of patients required secondary distal neurolysis. Complications remained low at 3% (3 seroma, 1 wound dehiscence). Conclusions: Patients diagnosed with the Human Disharmony Loop exhibit a dramatic clinical improvement following pectoralis minor release. A medial coracoid pectoralis minor block injection can aid in diagnosis but does not rule-out the syndrome. Patients showed significant reductions in shoulder pain, headaches, concomitant neuropathic lesions and improved shoulder range of motion. Patients should be counseled that some may need secondary neurolysis for residual neuropathy.

Background: Subacromial impingement or pain syndrome (SAPS) is the most common diagnosis for chronic shoulder pain. Current surgeries do not reduce long-term pain, suggesting they miss the root etiology. Previously, we described the Human Disharmony Loop (HDL), where the unique lower trunk innervation to the pectoralis minor (PM) causes scapular dyskinesis and deforms its connections, including tugging the acromion down and impinging the subacromial structures. We hypothesize that SAPS patients who meet HDL criteria would benefit significantly from PM tenotomy with infraclavicular brachial plexus neurolysis (PM + ICN) alone. Methods: SAPS patients who met HDL diagnostic criteria were treated with PM + ICN, with secondary distal neurolysis if needed. Outcomes included pain and shoulder abduction ROM. Six-month follow-up minimum was required. Results: N = 140 patients were included. Median age was 49. Prior surgeries included 27% subacromial decompression/acromioplasty, 21% rotator cuff repair, 16% biceps tenodesis, 4% SLAP repair, 2% labral repair, 7% distal clavicle resection, 10% reverse total shoulder arthroplasty (rTSA), 1% rib resection with scalenectomy, 16% cervical spine fusion, 28% distal neurolysis. Median pain decreased from 8 to 2 and median shoulder ROM increased from 90 to 180 degrees. Positive impingement signs on exam decreased from 100% to 11%. (p < 0.01) Conclusions: In a large series of SAPS patients, evaluation and treatment for the HDL significantly reduced pain and restored motion. These findings suggest that in many patients SAPS may be a subset of the HDL: the ventral PM disturbing the scapula constitutes the anatomic basis and optimal surgical target behind SAPS.

Background/Objectives: Many patients evaluated by shoulder specialists suffer from intractable pain, neuropathy, and weakness. The pectoralis minor (PM) remains the only scapula muscle to receive lower trunk (C8-T1) input. We propose a novel, unifying musculoskeletal and neurologic syndrome: the Human Disharmony Loop. This model portrays how this unique PM innervation causes scapular dyskinesia which deranges the anatomy of the upper limb girdle and produces a refractory symptom complex of pain, neuropathy, and weakness. Methods: Ten patients of diverse etiologies presented with a similar constellation of complaints. Patients included: female athlete, female with macromastia, male bodybuilder, post-radiation breast cancer, postoperative shoulder arthroplasty, interscalene block injury, cervical spine disease, persistent impingement after rotator cuff repair, direct traction injury, and occupational disorder. All patients exhibited coracoid tenderness, scapula protraction with internal rotation and anterior tilt, and pain involving the neck, shoulder, and upper back. Patients demonstrated varying degrees of arm neuropathy, subacromial impingement, occipital headaches. Patients failed all prior treatments by multiple subspecialists including surgery. Each patient underwent isolated open PM tenotomy. Results: PM tenotomy completely resolved presenting signs and symptoms in all patients. This included elimination of shoulder, upper back, and neck pain, clearance of concomitant neuropathy, resolution of rotator cuff impingement, restoration of full motion, and eradication of headaches. Response to surgery was rapid, dramatic, and durable. Conclusions: The unique asymmetric neurologic innervation to the sole ventral stabilizer of the scapula, the pectoralis minor, predisposes the human shoulder to neurologic and musculoskeletal imbalance. This produces the Human Disharmony Loop: a clinical syndrome spanning the neck to the fingertips of chronic pain, neuropathy, and weakness. These challenging patients may benefit dramatically from isolated PM tenotomy.

Background: Subacromial impingement or pain syndrome (SAPS) is the most common cause of chronic shoulder pain. Current surgeries do not reduce long-term pain, suggesting they miss the root etiology. Previously, we described the Human Disharmony Loop (HDL), where the unique lower trunk innervation to the pectoralis minor (PM) tips the scapula into dyskinesis and deforms its connections, including tugging the acromion down and impinging the subacromial structures. We hypothesize that SAPS patients who meet HDL criteria would benefit significantly from PM tenotomy. Methods: Patients with SAPS who met HDL diagnostic criteria were treated with PM tenotomy and brachial plexus neurolysis, with additional secondary distal neurolysis if needed. Outcomes included pain and shoulder ROM in the abduction plane. 6-month follow-up minimum was required. Results: N = 140 patients were included. Median age was 49. Prior surgeries included 27% subacromial decompression/acromioplasty, 21% rotator cuff repair, 16% biceps tenodesis, 4% SLAP repair, 2% labral repair, 7% distal clavicle resection, 10% re-verse total shoulder arthroplasty (rTSA), 1% rib resection with scalenectomy, 16% cervical spine fusion, 28% distal neurolysis. Median pain decreased from 8 to 2 and median shoulder ROM increased from 90 to 180 degrees. Positive impingement signs on exam decreased from 100% to 11%. (p< 0.01) Conclusions: In a large series of SAPS patients, evaluation and treatment for the HDL significantly reduced pain and restored motion. These findings strongly suggest that SAPS itself is a subset of the HDL: the ventral PM disturbing the scapula constitutes the anatomic basis and optimal surgical target behind SAPS.