Conditions that get confused, compared
Some conditions sit close enough together that people (and sometimes clinicians) get them mixed up. These pages lay the patterns side by side. Where the pain points, what triggers it, which clinical tests separate them, and what I check in clinic when I am not sure yet.
Comparisons available
Tennis elbow vs. Golfer's elbow
Both are tendinopathies at the elbow, and the names are misleading. Tennis elbow sits on the outside of the elbow at the lateral epicondyle, where the wrist extensor tendons meet the bone. Golfer's elbow sits on the inside, at the medial epicondyle, where the wrist flexor and forearm pronator tendons attach. Same tissue type, opposite sides, different provocation patterns. People end up confusing them because the pain can spread down the forearm in both cases.
Rotator cuff vs. Frozen shoulder
Both cause shoulder pain and both make it hard to use the arm, but the mechanics are different. Rotator cuff problems are tendon and muscle driven, which means the cuff hurts and weakens but the joint can usually still be moved by someone else. Frozen shoulder (adhesive capsulitis) is a capsule problem, which means the whole joint stiffens up so badly that even a physio cannot move it past a certain point. That is the crucial separator, and it is why they need very different plans.
Patellar tendinopathy vs. Patellofemoral pain
Both sit at the front of the knee and both flare with loaded knee bending. The difference comes down to where the pain points and what triggers it. Patellar tendinopathy is a localised tendon overload problem. The pain sits at the bottom tip of the kneecap on the tendon, flares with jumping and changes of direction, and eases as the tendon warms up. Patellofemoral pain is a loading and tracking problem at the joint surface behind the kneecap. The pain is more diffuse, flares with stairs, prolonged sitting, and running, and does not warm up in the same way.
Sciatica vs. Piriformis syndrome
Both can send pain from the buttock down the back of the leg, and both get lumped together as 'sciatica' in everyday language. True sciatica is nerve-root irritation at the lumbar spine, most often from a disc, that produces a dermatomal pattern of symptoms and, in more involved cases, changes in reflexes, strength, or sensation. Piriformis syndrome, now often discussed under the broader heading of deep gluteal syndrome, is compression or irritation of the sciatic nerve in the buttock itself, below the spine. Same nerve, different location. The leg symptoms can look similar on the surface, but the history, provocation pattern, and exam findings separate them.
Hip OA vs. GTPS / lateral hip
Both present as hip pain in middle-aged and older adults, and both get called 'a hip problem' casually, but they live in different tissues. Hip osteoarthritis is a joint problem. Pain sits deep in the groin, range of motion is restricted, and internal rotation is the movement that suffers first. Greater trochanteric pain syndrome, which is mostly gluteal tendinopathy with or without associated bursitis, is a tendon and soft tissue problem on the outside of the hip. The point of tenderness is on the bony bump of the greater trochanter, range of motion at the hip is usually preserved, and the pain pattern is dominated by compression, side-lying, and single-leg loading rather than by stiffness.
ACL injury vs. Meniscus tear
Both commonly follow a twisting knee injury, and both show up frequently in skiers, court sports, and soccer. They often travel together too. The classic O'Donoghue triad combines ACL rupture, medial collateral ligament injury, and a medial meniscus tear. Despite the overlap, the mechanism, swelling timing, exam findings, and natural history differ enough that the two can usually be separated clinically in the first visit. The reason this matters is practical: the management decisions, timelines, and return-to-sport plans look quite different.