Shoulder Surgery Risks: Infection, Nerve Damage, Stiffness, Re-tear

Table of Contents

How risky is shoulder surgery overall?

Shoulder surgery carries a 1-4% overall complication rate, placing it among the safer categories of orthopedic surgery. The risk profile is not uniform, though: each complication has its own frequency, its own warning signs, and its own high-risk window. This page covers the 6 that matter, ordered by how often they occur.

The numbers below are population averages. Your personal risk moves with 4 factors — age, smoking status, diabetes control, and procedure type — and the final section shows how much each one moves it.

Risk #1: stiffness and frozen shoulder (5-15%)

Post-operative stiffness is the most common complication of shoulder surgery, affecting 5-15% of patients, and it is also the most treatable.

The joint capsule responds to surgical trauma and immobilization by laying down scar tissue. Caught early, stiffness resolves with extended physical therapy in over 90% of cases; the entrenched version (adhesive capsulitis) takes 6-18 months and sometimes a second arthroscopy to release.

Prevention is concrete: complete every prescribed passive-motion session in Weeks 1-6. The PT phases page explains why early passive motion blocks scar formation without loading the repair.

Risk #2: re-tear after rotator cuff repair (10-40%)

The repaired rotator cuff tendon fails to heal or tears again in 10-40% of cases — 10% for small tears, rising to 30-40% for massive tears in patients over 65.

Three facts put that alarming range in context:

Most re-tears happen in the first 3 months, while tendon-to-bone healing is incomplete — which is why the 6-week sling and the lifting restrictions exist.
Many re-tears stay functional. Pain relief often survives the re-tear; studies show 70-80% of re-tear patients still rate their outcome as good.
The strongest patient-controlled protections are mechanical: no lifting beyond the limit, no leaning on the operated arm, and protected sleep positioning for the first 6 weeks per the rotator cuff sleep protocol.

Risk #3: infection (0.5-2%)

Deep infection follows shoulder surgery in 0.5-2% of cases — under 1% for arthroscopy, 1-2% for open procedures and replacements.

The shoulder has one unusual culprit: Cutibacterium acnes, a skin bacterium concentrated around the shoulder that causes indolent, slow-burning infections — more common in men under 60 and after open surgery.

Call the surgeon the same day if any of these 4 signs appears: fever over 38.3°C (101°F), spreading redness around the incision, drainage after Day 5, or pain that worsens after Week 1 instead of easing. Early superficial infections clear with 1-2 weeks of antibiotics; deep prosthetic infections require revision surgery, which is why the call is urgent.

Risk #4: nerve injury (1-4%)

Nerve injury complicates 1-4% of shoulder surgeries, and the overwhelming majority are temporary stretch injuries (neurapraxia) that recover within 3-6 months.

Two nerves dominate the statistics: the axillary nerve (deltoid weakness, numb patch over the outer shoulder) and the brachial plexus during replacement surgery (mixed arm symptoms). Permanent injuries occur in fewer than 1 in 300 cases.

Report numbness or new weakness at the first post-op visit — documented early, a stretch injury gets monitored; missed, it gets confused with rehab plateau months later. The follow-up schedule page lists what each visit screens for.

Risk #5: blood clots (0.2-0.6%)

Deep vein thrombosis and pulmonary embolism are rare after shoulder surgery — 0.2-0.6%, roughly 10× lower than after hip or knee replacement, because you walk the same day.

The signs still warrant a same-day call: calf swelling or pain on one side, sudden shortness of breath, or chest pain. Patients with prior clots, clotting disorders, or active cancer get prophylactic blood thinners; everyone else gets early mobilization, which you control.

Risk #6: anesthesia complications (under 1%)

Serious anesthesia complications occur in fewer than 1% of shoulder surgeries. The procedure-specific item is the interscalene nerve block: it temporarily paralyzes half the diaphragm in most patients, which healthy lungs never notice but severe COPD patients do.

The anesthesia page covers the general-plus-block combination, who gets which option, and the block’s 12-24 hour timeline — including why you take the first pain dose before the block wears off.

How the risks stack by procedure

Each procedure carries one signature risk plus a 1-5% overall complication rate, compared here side by side:

Procedure	Signature risk	Overall complication rate
Arthroscopy	Persistent symptoms	1-2%
Labrum repair	Re-dislocation (5-10%)	2-4%
Rotator cuff repair	Re-tear (10-40%)	2-4%
TSA / reverse TSA	Infection, implant loosening	3-5%
AC reconstruction	Loss of reduction (10-20%)	3-5%

Procedure details for all 6 operations are on the surgery types overview.

The 4 risk factors you can actually change

Modifiable risk factors move complication rates more than procedure choice does:

Stop smoking 4-6 weeks before surgery. Smoking doubles infection risk and roughly doubles rotator cuff re-tear risk — the single largest modifiable factor.
Bring HbA1c under 7.5% if diabetic. Poor glucose control multiplies infection risk 2-3×; most surgeons postpone elective surgery above 8%.
Complete prehab. 4-6 weeks of pre-operative strengthening correlates with faster motion recovery and lower stiffness rates.
Set up sleep before surgery, not after. Protected positioning failures — rolling onto the operated arm in Week 2 — are a preventable re-injury source. The wedge vs cradle decision page matches the setup to your procedure, and the preparation checklist puts it in the pre-op timeline.