Lumbar Spine Fusion

Adam E.M. Eltorai, MD

Alan H. Daniels, MD

Dr. Daniels or an immediate family member serves as a paid consultant to DePuy, A Johnson & Johnson Company, Globus Medical, Orthofix, and Stryker; serves as an unpaid consultant to Osseus; and has received research or institutional support from Orthofix. Neither Mr. Eltorai nor any immediate family member has received anything of value from or has stock or stock options held in a commercial company or institution related directly or indirectly to the subject of this article.

Introduction

The goal of lumbar spine fusion surgery is to alleviate pain, numbness, paresthesias, and/or weakness due to vertebral segment pathology or instability. Each of the various surgical approaches includes adding a bone graft or bone graft substitute to elicit physiologic bony union of adjacent vertebrae to reduce motion.

Lumbar Spine Fusion

Indications

Indications for lumbar spine fusion include select cases of degenerative disc disease; spondylolisthesis (isthmic, degenerative, or postlaminectomy); spinal stenosis; instability (as measured by anterior/posterior translation or endplate angulation); fractures; tumors; infections; and deformity (such as scoliosis, lordosis, or kyphosis).

Contraindications

There are several factors that may negatively impact the outcome of spinal fusion surgery. These relative contraindications include current smoking status; multilevel degenerative lumbar disease; disability >1 year prior to consideration of fusion; failure to return to work for ≥6 months after previous spine surgery; being severely deconditioned; and psychiatric comorbidities, including factitious disorder, somatization, or history of substance abuse.

Procedure

Relevant Anatomy

Figures 63.1 and 63.2 show the anatomy that is relevant to lumbar spine fusion.

Techniques

There are numerous lumbar fusion surgery techniques available. The most common operations include posterolateral gutter fusion, posterior lumbar interbody fusion (PLIF), transforaminal lumbar interbody fusion (TLIF), far-lateral lumbar interbody fusion (XLIF), anterior lumbar interbody fusion (ALIF), and anterior/posterior (AP) lumbar fusion.

Posterolateral gutter fusion surgery involves the placement of bone graft in the posterolateral portion of the spine. In PLIF, bone graft and/or an interbody cage is placed into the disc space in the front of the spine. TLIF involves the removal of an entire facet joint, enabling greater disc space access and less neural retraction than PLIF. During ALIF surgery, bone graft is placed with a plate or interbody cage within the cleared disc space through an incision in the abdomen. XLIF surgery is performed through a lateral incision and allows access to the upper lumbar vertebral levels (L1–L4). AP lumbar fusion can achieve the greatest stability, but requires anterior and posterior incisions combining XLIF or ALIF and posterolateral gutter fusion procedures.

Complications

As with any type of surgery, there is a risk of infection, bleeding, and anesthetic complications. Specific postoperative complications of lumbar spine fusion include failure to alleviate lower back pain; pseudoarthrosis (when the vertebrae do not fuse together properly); pedicle screws may break or loosen; migration of anterior grafts or cages; and nerve damage that may result in loss of leg strength or sensation, loss of bowel or bladder control, or ejaculation difficulty (especially in anterior L4–S1 fusion surgeries).

Postoperative Rehabilitation

Introduction

Early physical therapy consultation makes postoperative rehabilitation more successful. Although surgical technique and unique patient characteristics will dictate certain aspects of rehabilitation (such as the use of brace or bone growth
stimulation), there are general rehabilitation principles that all lumbar fusion surgery patients should keep in mind. First and foremost, rehabilitation requires time and energy commitment. Preoperatively, patients should understand that the surgery is just the beginning of the healing process. Although the traditional teaching following lumbar fusion was to avoid all twisting and bending postoperatively, it is now believed that some torso movement may be beneficial; modern fixation techniques allow for safe mobility postoperatively following lumbar spinal fusion. While twisting, bending, and lifting
should be avoided initially, gentle stretching, strengthening, and conditioning are beneficial as they promote restorative blood flow, activation of stabilizing support muscles, and continued flexibility in addition to prevention of venous thromboembolism. Bone fusion achieves initial maturity by 3 to 6 months, although it may take years for the fusion to completely mature. Gentle stress on the graft actually promotes bone growth; therefore, activity and mobility are beneficial.

Figure 63.1 Illustration of muscles of the back. (Reproduced with permission from Tank PW, Gest TR: Lippincott Williams & Wilkins Atlas of Anatomy. Baltimore, Wolters Kluwer Health, 2009.)

Figure 63.2 Illustration of surgical anatomy and technique.

Authors’ Preferred Protocol

Immediately postoperatively, the patient can begin stretching, stabilization exercises that do not involve trunk movement, and walking, as tolerated.
By postoperative week 6, stabilization exercises that involve trunk movement should be incorporated. Goals progress toward improving lumbar and core strength.
By postoperative week 9, aerobic conditioning should be incorporated to improve overall fitness and help burn excess body weight that may strain the lumbar spine (Table 63.1).

Stretches: Low Back, Hamstrings, and Quadriceps

Low Back

Stretching the low middle back may help prevent adhesions of the nerve roots.
Lie on the back with legs on the ground, slowly lift one leg until stretch is felt in the lower back.
Use a hand to support the raised leg and extend your ankle in a “pumping the gas” motion for 5 to 10 seconds.
Switch legs.
Repeat every two hours (Figure 63.3).

Hamstrings: Lying or Seated Options

Lying Option

Lie on the back, bend both knees.
Straighten one leg and use a hand to support the raised leg.
Push heel toward the ceiling until a stretch is felt in the back of the thigh.
Hold for 30 seconds.
Switch legs.
Repeat 3 times, twice a day (Figure 63.4).

Seated Option

Sit on the edge of the chair.
Straighten one leg with toes up and heel on the ground.
Hold the sides of the chair and move your bottom off the chair.
Keep the chest up while feeling a stretch in back of the extended thigh.
Hold for 30 seconds.
Switch legs.
Repeat 3 times, twice a day (Figure 63.5).

Quadriceps

Lie on the stomach.
Bring the heel as close to your bottom as you can.
Hold for 30 seconds.
Switch legs.
Repeat 3 times, twice a day (Figure 63.6).

Pelvic Tilt

Lie on the back with bent knees.
Push the back to the floor, straightening the back and tilting the pelvis.
Hold for 20 seconds.
Repeat 3 times, twice a day (Figure 63.7).

Table 63.1 REHABILITATION PROGRAM FOR LUMBAR SPINE FUSION SURGERY

Exercise Type	Main Muscle Groups	Number of Repetitions/Sets	Number of Days per Week	Number of Weeks
Low back stretch	Erector spinae (iliocostalis, longissimus, spinalis), latissimus dorsi	2 repetitions/8 sets	7	Postop day 1 and onward
Hamstring stretch	Hamstrings (semitendinosus, semimembranosus, biceps femoris)	3 repetitions (30-s holds)/2 sets	7	Postop day 1 and onward
Quadriceps stretch	Quadriceps (vastus lateralis, vastus intermedius, vastus medialis, rectus femoris)	3 repetitions (30-s holds)/2 sets	7	Postop day 1 and onward
Pelvic tilt	Erector spinae, latissimus dorsi	2 repetitions (15-s holds)/2 sets	7	Postop day 1 and onward
Lying march	Quadriceps	“March” for 30 s/4 sets	7	Postop day 1 and onward
Bridge	Gluteus maximus/medius, hamstrings, abdominals (rectus abdominis, internal/external obliques)	5–10 repetitions/2 sets	7	Postop day 1 and onward
Back extension	Trapezius, latissimus dorsi, erector spinae	3 repetitions/2 sets	7	Postop day 1 and onward
Prone hip extension	Hamstrings	3 repetitions/2 sets	7	Postop day 1 and onward
Seated row	Trapezius, latissimus dorsi, erector spinae, teres major/minor	5 repetitions/2 sets	5	Postop day 1 and onward
Diagonal abdominal curls	Erector spinae, abdominals (+ transverse abdominis), quadratus lumborum	5–10 repetitions/2 sets	5	Postop week 6 and onward
Opposite limb raise	Trapezius, erector spinae, deltoid, gluteus maximus/minimus, quadriceps, hamstrings	3–5 repetitions/2 sets	5	Postop week 6 and onward
Lean back	Trapezius, latissimus dorsi, erector spinae	Hold for 30 s/3 sets	5	Postop week 6 and onward
Oblique pull	Abdominals, deltoid, latissimus dorsi	5–10 repetitions/2 sets	5	Postop week 6 and onward
Exercise ball opposite limb lift	Triceps brachii, transverse abdominis, serratus posterior, psoas, iliacus	10–20 repetitions/1 set	5	Postop week 6 and onward
Exercise ball leg extension	Hamstrings	5–10 repetitions/1 set	5	Postop week 6 and onward
Hip raise	Gluteus maximus/medius, hamstrings, abdominal	5–10 repetitions/1 set	5	Postop week 6 and onward
Aerobic conditioning	All organ systems	≥30 min	5	Postop week 9 and onward