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Osteochondral allograft transplantation in the knee is an alternative to knee joint replacement that may be used to treat a young and healthy population with symptomatic cartilage defects. The defect may be identified by MRI and/or arthroscopy. When conservative management has failed, a diagnostic arthroscopy is indicated to assess the location, size, and severity of the defect(s). These findings determine what method is best suited for cartilage restoration. Osteochondral allograft transplantation is indicated for large lesions that have affected the knee cartilage and subchondral (beneath cartilage) bone. Osteochondral allografts are composed of fresh donor tissue and are procured from tissue banks that follow strict safety guidelines. This article will take you through a case study demonstrating an arthroscopic evaluation, osteochondral allograft cartilage transplant, and sample phase 1 knee rehab exercises!
NONSURGICAL TREATMENTS
Before we jump into the knee surgery itself, we want to reiterate that conservative, non-surgical options should always be exhausted first! Non-surgical treatment options for the knee include activity modification, icing, bracing (if bow-legged or knock-kneed), physical therapy, anti-inflammatory supplements (glucosamine and chondroitin), medications (oral anti-inflammatories like ibuprofen, Aleve [naproxen], Celebrex [celecoxib]) and/or injections (cortisone, hyaluronic acid viscosupplementation, platelet-rich plasma). When non-surgical treatment options have been exhausted, we need to take a look at surgical options to get individuals back to full function.
SURGICAL TREATMENTS
Surgical treatment varies depending on the size, location, and depth of the cartilage defect as well as patient activity level and long-term goals. In order of increasing invasiveness, surgical treatment options include debridement (cartilage shaving), microfracture (drilling subchondral bone to release bone marrow elements), and autologous chondrocyte implantation (cell transplant), osteochondral autograft (your tissue), and osteochondral allograft (cadaver tissue). Osteochondral allograft is a surgery that treats knee cartilage lesions with a transplant of cadaver bone and cartilage. Below is surgery from Dr. Brian Cole.
Osteochondral Allograft Arthroscopic Evaluation
A wide spectrum of chondral diseases exists, ranging from superficial articular cartilage injuries to larger, full-thickness osteochondral lesions. While some lesions remain asymptomatic, others can be debilitating and prevent a patient from living their desired lifestyle. Observation of focal chondral pathology in the knee is common during knee arthroscopy, and treatment considerations are dependent on the size, location, and depth of the defect. The next few images will take you through an arthroscopic evaluation of a chondral lesion.
This patient is a young athlete presenting with osteochondral dissecans of the femur, a condition where lack of blood supply causes fragments of cartilage and bone to separate from the surrounding tissue. This often leads to loose bodies in the knee, knee pain, and joint effusion.
The lesion above is measured at 16 x 16 mm. Think of this like a pothole in the road!
CARTILAGE TRANSPLANT- OSTEOCHONDRAL ALLOGRAFT
The ideal candidate for cartilage restoration surgery is the symptomatic young, motivated individual with either normal or correctable comorbidities.
The defect is exposed via an open incision. Note the visible difference between smooth, healthy cartilage and the defect.
After the defect size is confirmed, a drill of matching diameter is used to shape the defect in preparation for the graft.
The graft is prepared. It is cut to the size of the defect and washed with a pulse lavage for sterility. The graft is soaked in bone marrow aspirate concentrate (BMAC) for patients electing to supplement the procedure with stem cells. Rush is currently conducting research to determine if BMAC can improve graft integration. The osteochondral plug is press-fit into the prepared defect! We need to make sure individuals protect the operated site well after surgery.
Having Trouble Regaining Knee Extension After Surgery?
Knee extension is arguably the most important movement to recover first after knee surgery. If you are having difficulty straightening your knee, this program is perfect for you! The Knee Extension Overhaul [P]Rehab Program is the ultimate resource for those looking to regain full knee extension – whether that’s before surgery or after. The importance of full knee extension for functional demands and life, in general, is crucial! Ask any orthopedic surgeon or rehabilitation specialist, NOW is the time to regain your full knee extension. Click HERE to learn more!
Osteochondral Allograft Post-Operative Exercises: Mobility
Exercise 01 of 05
Exercise demonstration
Ankle Pump - Elevated
View exercise instructions
- HOW: Get set up laying flat on your back with your legs elevated above heart level. To begin the exercise, move your ankle forward and backward in a pumping motion. The goal is to get comfortable with this forward and backward ankle range of motion.
- FEEL: You should feel all different parts of your ankle stretching and activating.
- COMPENSATION: Move just from the ankle, not the toes.
After surgery, it is very common to have swelling and edema in the knee. To help control the swelling and prevent a serious complication called deep vein thrombosis from forming in your calf, it is imperative to perform ankle pumps. Contracting your calf muscle keeps blood flowing in the veins and arteries and helps decrease swelling in the knee. To perform this exercise lie on your back or sit with your feet out Point your toes down then back up again.
Exercise 02 of 05
Exercise demonstration
Seated Knee Extension - PROM
View exercise instructions
- HOW: Get into a comfortable position on a chair or bed with your foot elevated and supported on a surface so that your leg is straight and parallel to the ground. Let gravity pull your knee into extension and/or use your hands as needed to help move your knee into extension. Hold until your knee begins to feel a little uncomfortable – not painful. Then relax your leg. Repeat as needed or prescribed.
- FEEL: This should feel like a stretch behind your knee, maybe even your calf and hamstring. It can be normal sometimes to feel discomfort in the front of the knee, try to readjust your position if it is not tolerable discomfort. See video for other tips.
- COMPENSATION: Do not let your foot rotate out to the side. Make sure to only prop your foot on the chair so there is an empty space under your knee.
Repeat every hour.
Exercise 03 of 05
Exercise demonstration
Runner's Knee? Improve your kneecap mobility
- Position yourself long-sitting with your legs and bottom supported on a surface. Also, keep your back supported if possible
- Using the webspace of your hand or your fingers, gently mobilize your patella (kneecap) in all four directions (up, down, side-to-side) and hold each position for ten seconds. You should not be putting pressure down on your knee cap as this may be uncomfortable, instead focus on gliding your kneecap in all four directions. Repeat as prescribed.
- Use your other knee cap as a reference for how your kneecap on your affected knee should ideally move.
How to Use Crutches the Right Way - Your [P]rehab Crutches Crash Course
Exercise 04 of 05
Exercise demonstration
Quad Set
View exercise instructions
- HOW: Follow this foolproof guide to wake your quad back up! Laying on the ground or on a table with your knee straight and foot supported, attempt to push your knee down and lift your heel off the ground by squeezing your quadriceps muscle until your knee is fully straight. return to starting position and repeat.
- FEEL: Really focus on squeezing your quad. Sometimes touching the muscle, massaging it, or hitting it can help. Think about moving your kneecap up and towards your hip socket. Push your knee down into the ground. Move your shin bone in the shape of a “J” by moving your knee down and your heel up at the same time. Squeeze both quadriceps at the same time to improve the quality of the quad contraction.
- COMPENSATION: Do not lift your entire leg off the ground, focus on getting your knee fully straight similar to the other side.
This exercise (quad set) is paramount to getting re-gaining active control of your quadriceps muscles, which is the muscle on the front of your thigh. After an injury (which includes surgery), there is lots of swelling in the knee that accumulates. This swelling leads to a phenomenon called atherogenic inhibition, in which there is an inability to completely contract a muscle despite no injury to the muscle or innervating nerve. To combat this, lots of practice and developing a new “brain-body connection” is required.
Laying on the ground or table and place a rolled-up towel/shirt under your knee. This will act as a lever which will make it easier to activate your quadriceps muscle. Attempt to squeeze your quadriceps muscle using these cues.
- Really focus on squeezing your quad
- Sometimes touching the muscle, massaging it, or hitting it can help
- Think about moving your kneecap up and into your hip socket
- Push your knee down into the towel roll
- Lift your heel off the table
- Move your shin bone in the shape of a “J” by moving your knee down and your heel up at the same time
- Squeeze both quadriceps at the same time
Exercise 05 of 05
Exercise demonstration
Side Lying Hip Abduction - Core Activation
View exercise instructions
- HOW: Begin on your side with your leg on top straightened out. First contract your core, you can push your elevated arm into the arm that is towards the floor, this will assist in creating some core stiffness. Then elevate the top leg towards the ceiling and back wall simultaneously. Avoid crunching at your low back or rotating your body open towards the ceiling.
- FEEL: You should feel the outer hip, particularly the glute muscles with this exercise. You can place your top hand on your pelvis to assure the motion is coming from the hip and not the lower back.
- COMPENSATION: Avoid rotating your entire trunk or performing a side crunch with this exercise. Make sure the shoulder that is facing the ceiling stay in front of the shoulder that is against the floor.
- Lie on your side with your affected leg on top
- Bend your bottom leg
- Slightly squeeze your core. Maintain this activation throughout the entire exercise
- Push your bottom knee into the ground to keep your pelvis stable
- Straight your top leg and lift it up and back. The key is that you are not just lifting the leg up, but also BACK a bit
- You should feel a deep muscle burning in the back of your hips where your glutes are, not in the front of your hips. If you feel it in the front of your hips, make sure your hips are pointed directly ahead of you and not up to the sky, and also check that you are lifting the top leg backward
Closing Thoughts
- Osteochondral allograft is an outpatient surgery that may take 45 minutes to 2 hours, depending on the size, location, and number of lesions being treated.
- Most patients require pain medication for 1 to 2 weeks following surgery.
- Most patients start physical therapy the week after surgery.
- Most patients use a continuous passive motion (CPM) machine for 6 to 8 hours/day for 6 weeks.
- Most patients use crutches and are non-weight bearing for the first 6 weeks following surgery, and gradually return to full weight-bearing over 8 to 12 weeks.
- Return to sports activities is typically initiated at 8 months following surgery.
It is to note that rehabilitation protocol is dependent upon transplant location, in this case, the femoral condyle. See briancolemd.com for additional rehabilitation protocols and more literature on cartilage restoration. When used in the appropriate cases, osteochondral allograft transplantation is clinically proven to have favorable outcomes and high rates of satisfaction. It is a viable alternative to joint replacement in young, healthy patients with symptomatic cartilage defects.
How To Ensure Your Knee Gets The Motion It Needs After Surgery
Knee extension is not just a recommendation it is needed! Hypothetically, you could walk on a bent knee but this is going to waste energy and ultimately limit your movement endurance. Instead, let's get you moving efficiently by achieving and keeping full knee extension.
REFERENCES
- Frank RM, Lee S, Cotter EJ, Hannon CP, Leroux T, Cole BJ. Outcomes of Osteochondral Allograft Transplantation With and Without Concomitant Meniscus Allograft Transplantation: A Comparative Matched Group Analysis. Am J Sports Med. 2018; 46(3): 573-580.
- McCarthy MA, Meyer MA, Weber AE, Levy DM, Tilton AK, Yanke AB, Cole BJ. Can Competitive Athletes Return to High-Level Play After Osteochondral Allograft Transplantation of the Knee? Arthroscopy. 2017; 33(9): 1712-17.
- Cotter EJ, Frank RM, Wang KC, Cole BJ. Rehabilitation and Return to Play Following Osteochondral Allograft Transplantation in the Knee. Oper Tech Sports Med. 2017; 25: 208-213.
- Chahal J, Gross AE, Gross C, Mall N, Dwyer T, Whelan D, Cole BJ: Outcomes of osteochondral allograft transplantation in the knee. Arthroscopy, 29 (3): 575-88, 2013.
- McCulloch PC, Kang RW, Sobhy MH, Hayden JK, Cole BJ. Prospective evaluation of prolonged fresh osteochondral allograft transplantation of the femoral condyle: Minimum 2-year follow-up. Am J Sports Med, 35: 411-420, 2007.
All photos are property of Brian Cole MD, MBA
For more information on basic science, technique, outcomes, and rehabilitation protocols visit briancolemd.com










